Home › Glossary
Reference

PDF glossary

203 PDF terms explained in plain English — from everyday operations like merging and compressing to the standards, encryption schemes and browser technology underneath. 91 of them map to a tool on this site; the rest are here because they come up and deserve a straight answer.

Converting between formats

Terms for turning other file types into PDF, and PDFs into other formats.

BMP to PDF

Converting uncompressed Windows bitmap images into PDF pages.

Not offered here

DWG to PDF

Converting AutoCAD drawing files into PDF plots for sharing with people who have no CAD software.

Not offered here

DXF to PDF

Converting the open CAD interchange format into PDF for viewing and printing.

Not offered here

EPUB to PDF

Converting a reflowable ebook into fixed PDF pages. The reflowable text has to be committed to a specific page size, which is a lossy decision.

Not offered here

Excel to PDF

Converting a spreadsheet into PDF pages. Print settings matter far more than the converter here, since column widths and page breaks decide how the sheet is split across pages.

Not offered here

GIF to PDF

Placing GIF images into a PDF. PDF has no concept of animation, so an animated GIF is reduced to a single still frame.

Not offered here

HEIC to PDF

Converting Apple's High Efficiency Image Format photos into PDF. Many tools cannot read HEIC directly and convert to JPEG first.

Not offered here

HTML to PDF

Rendering a web page or HTML markup into a PDF. Every browser does a version of this through Print to PDF.

Not offered here

JPG to PDF

Combining one or more JPEG images into a single PDF, with each image placed on its own page.

Try the tool →

ODT to PDF

Exporting an OpenDocument text file, the native format of LibreOffice and OpenOffice, to PDF.

Not offered here

Pages to PDF

Exporting an Apple Pages document to PDF, which Pages does natively through its Export menu.

Not offered here

PDF Converter

A general term for any tool that translates a document between PDF and another format. Conversion quality varies enormously by direction: producing a PDF is reliable, while pulling structured content back out of one is much harder.

Partly covered →

PDF to CSV

Pulling data tables out of a PDF into comma-separated values for use in a spreadsheet or database.

Not offered here

PDF to DWG

Recovering vector geometry from a PDF into an editable CAD drawing. Layer names, blocks and dimensions are generally lost.

Not offered here

PDF to EPUB

Adapting fixed PDF pages into a reflowable ebook format so text can resize on a reader. Results depend heavily on how cleanly the PDF's reading order is defined.

Not offered here

PDF to Excel

Extracting tabular data from a PDF into spreadsheet cells. Accuracy depends on whether the PDF has real table structure or just visually aligned text.

Not offered here

PDF to HTML

Transforming PDF content into web markup. Output is usually heavily positioned with absolute coordinates rather than clean semantic HTML.

Not offered here

PDF to JPG

Rendering each page of a PDF as a standalone JPEG image, usually delivered as a ZIP when the document has many pages.

Try the tool →

PDF to JSON

Extracting text, positions and metadata from a PDF into JSON, commonly used in data pipelines and document automation.

Not offered here

PDF to ODT

Converting a PDF back into an editable OpenDocument file, with the same structural limits as PDF to Word.

Not offered here

PDF to Pages

Opening PDF content in Apple Pages as an editable document.

Not offered here

PDF to PNG

Rendering PDF pages as PNG images. PNG is lossless and supports transparency, though a rendered page normally has an opaque white background unless the renderer is explicitly told otherwise.

Not offered here

PDF to PPT

Turning PDF pages into PowerPoint slides. Most converters place each page as a flat image rather than producing genuinely editable slide objects.

Not offered here

PDF to PSD

Importing PDF pages into Photoshop. Pages arrive rasterised, not as the editable layers of the original design.

Not offered here

PDF to RTF

Converting a PDF into Rich Text Format, an older editable document format readable by almost any word processor.

Not offered here

PDF to SVG

Extracting the vector artwork from a PDF page as an editable SVG file.

Not offered here

PDF to TXT

Extracting the raw text content of a PDF with no formatting. Works only on PDFs that contain a real text layer; scanned pages need OCR instead.

Partly covered →

PDF to WEBP

Rendering PDF pages as WebP images, which are typically smaller than equivalent JPEGs at similar quality.

Not offered here

PDF to Word

Extracting text, tables and layout from a PDF into an editable .docx file. This is genuinely difficult, because a PDF stores positioned glyphs rather than paragraphs, so the converter has to reconstruct structure that was discarded when the PDF was made.

Not offered here

PDF to XML

Parsing a PDF's text and structure into machine-readable XML for automated processing.

Not offered here

PNG to PDF

The same operation as JPG to PDF but for PNG images. Our JPG to PDF tool accepts PNG files directly.

Try the tool →

PostScript to PDF

Converting PostScript, the page description language PDF grew out of, into PDF. The classic tool for this is Ghostscript's ps2pdf.

Not offered here

PPT to PDF

Exporting a presentation to fixed-layout PDF, typically one slide per page. PowerPoint and Keynote both export this natively.

Not offered here

PSD to PDF

Exporting a layered Photoshop document to PDF. Layers are normally flattened into a single composited image.

Not offered here

RTF to PDF

Converting Rich Text Format documents into fixed-layout PDF.

Not offered here

SVG to PDF

Converting scalable vector graphics into PDF. Both formats are vector-based, so this can be done without any loss of quality.

Not offered here

TIFF to PDF

Wrapping TIFF images, often multi-page scans from office equipment, into a PDF container.

Not offered here

WEBP to PDF

Converting Google's WebP web image format into PDF pages.

Not offered here

Word to PDF

Exporting a .doc or .docx file to fixed-layout PDF so it displays identically everywhere. Word, Google Docs and LibreOffice all do this natively via Save As or Export.

Not offered here

XML to PDF

Rendering structured XML data into a formatted PDF, usually through a stylesheet that defines the layout.

Not offered here

XPS to PDF

Converting Microsoft's XML Paper Specification, a fixed-layout format that never displaced PDF, into PDF.

Not offered here

Editing pages and documents

Terms for changing the structure of a PDF: its pages, their order, their orientation and their size.

Bates Numbering

A sequential numbering scheme used in legal and medical document production, where every page across an entire set receives a unique identifier, often with a prefix. It is the standard way of referencing discovery documents in litigation.

Not offered here

Center PDF Content

Repositioning page content so it sits centred within the page boundaries, often needed after cropping or resizing.

Not offered here

Change PDF Margin

Adjusting the white space around page content, either by cropping the page or by scaling the content down within the same page size.

Not offered here

Combine PDF

Another name for merging. Some tools use it to mean combining mixed inputs, such as PDFs and images together, into one document.

Try the tool →

Compress PDF

Reducing a PDF's file size, mainly by downsampling and re-encoding the images inside it. Text and vector graphics can be left completely untouched, so they stay sharp and selectable.

Try the tool →

Crop PDF

Trimming the visible area of pages to remove margins or isolate a region. In PDF this changes the crop box rather than deleting content, so the trimmed area often still exists in the file.

Not offered here

Crop PDF Margins

Cropping specifically to cut away white space around the content, often to make scanned pages read better on a small screen.

Not offered here

Cut PDF

An informal term for splitting a PDF, or for removing a section of pages from it.

Try the tool →

Delete PDF Pages

Removing unwanted pages and saving a new document without them.

Try the tool →

Deskew PDF

Automatically straightening scanned pages that went through the scanner at a slight angle. Deskewing before OCR measurably improves recognition accuracy.

Not offered here

Despeckle PDF

Removing the scattered specks and noise that scanning introduces, particularly on older or photocopied documents.

Not offered here

Duplex PDF Split

Reassembling a document scanned in two passes — all the fronts, then all the backs — by interleaving the two sets back into the correct order.

Not offered here

Edit PDF

A broad term covering changes to the content inside a PDF: adding or altering text, drawing shapes, inserting images or redacting information. Because PDF stores positioned glyphs rather than editable paragraphs, true text editing is far harder than editing a Word file.

Not offered here

Extract PDF Pages

Copying a chosen set of pages into a new PDF while leaving the original untouched.

Try the tool →

Flatten PDF

Merging interactive elements — form fields, annotations, layers — into the static page content so they can no longer be edited or extracted, but always display identically.

Not offered here

Grayscale PDF

Converting a colour document to shades of grey, which reduces file size and avoids colour charges on commercial printing.

Try the tool →

Insert Pages to PDF

Adding pages from another document at a chosen position in the current one.

Partly covered →

Invert PDF Colors

Reversing the colours of a document, most often to produce light text on a dark background for comfortable night reading.

Not offered here

Join PDF Files

A plain-language synonym for merging PDFs.

Try the tool →

Merge PDF

Combining two or more PDFs into one continuous document. Pages are copied across intact, so there is no re-compression and no quality loss.

Try the tool →

N-Up PDF

Placing several document pages onto one physical sheet, such as two-up or four-up, to save paper when printing or to produce handouts.

Not offered here

Organize PDF

Viewing a document as a grid of page thumbnails so you can reorder and delete pages visually before saving.

Try the tool →

Overlay PDF

Drawing the content of one PDF on top of another, used for applying letterheads, stamps or comparison views.

Not offered here

Page Numbers PDF

Automatically inserting sequential numbers onto pages, with control over position, starting number and format.

Try the tool →

PDF Booklet Creator

Reordering and arranging pages for booklet printing, so that folding the printed stack in half produces correctly sequenced pages. This page ordering is called imposition.

Not offered here

PDF Compression Ratio

The relationship between a file's original and compressed size, often written as a percentage saved. A text-only PDF has very little to compress; an image-heavy scan has a great deal.

Try the tool →

PDF Page Counter

Simply reporting how many pages a document contains — useful for checking print costs or submission limits before uploading a file somewhere.

Partly covered →

PDF Page Orientation

Whether a page is portrait (taller than wide) or landscape (wider than tall). A single PDF can freely mix both.

Try the tool →

PDF Page Separator

A tool that separates every page of a document into an individual file, usually returned together in a ZIP archive.

Try the tool →

PDF Scaling

Enlarging or shrinking page content relative to the page, used to fit a document to a different paper size or to add a printing margin.

Not offered here

Rearrange PDF

Changing the sequence of pages within a document.

Try the tool →

Replace Pages in PDF

Swapping specific pages for pages from another file, keeping the rest of the document unchanged.

Not offered here

Resize PDF

Changing the physical page dimensions of a document, for example from US Letter to A4. Content is normally scaled to fit the new size.

Not offered here

Reverse PDF Page Order

Flipping a document so the last page becomes the first. Commonly needed after scanning a stack of paper face-up.

Partly covered →

Rotate PDF

Changing page orientation by 90, 180 or 270 degrees. A proper rotation tool writes the change into the file so it persists, unlike a viewer's temporary on-screen rotation.

Try the tool →

Split PDF

Dividing one PDF into several smaller files, either by page ranges you specify or by separating every page into its own document.

Try the tool →

Trim PDF

Another word for cropping the page edges.

Not offered here

Underlay PDF

The same operation as an overlay but placed behind the existing content, so the original page stays fully legible on top.

Not offered here

Watermark PDF

Stamping text or an image across pages, usually semi-transparent and diagonal, to mark a document as confidential, draft or copyright-protected.

Try the tool →

Security, signatures and annotation

Terms for protecting, signing, marking up and restricting PDF documents.

Add Ink to PDF

Drawing freehand on a page with a mouse, stylus or finger, stored as an ink annotation.

Try the tool →

Add Stamp to PDF

Applying a predefined mark such as APPROVED, DRAFT or a date stamp to a page.

Partly covered →

Add Text Box PDF

Placing a box of new text onto a page as an annotation or as added content.

Not offered here

AES Encryption

Advanced Encryption Standard, the modern cipher used by PDF 1.6 and later at 128-bit or 256-bit strength. It is the encryption you want for anything sensitive.

Partly covered →

Annotate PDF

Adding comments, notes, highlights or drawings to a document without altering the underlying content.

Not offered here

Audit PDF Security

Inspecting a document to report its encryption level, permission flags, signatures and any embedded content that could carry risk.

Not offered here

Batch Sign PDF

Applying the same signature to many documents in one operation, common in high-volume administrative work.

Not offered here

Black Out Text PDF

The everyday phrase for redaction. Worth knowing that a black box drawn on top of text is not redaction unless the text beneath is actually removed.

Not offered here

Decrypt PDF

Removing encryption from a document using the correct password, producing an unprotected copy.

Not offered here

Digital Certificate

The credential that makes a digital signature verifiable, issued by a certificate authority and binding an identity to a public key.

Not offered here

Digital Signature

A specific cryptographic technique that binds a signature to a document using a private key and a certificate, allowing anyone to verify both who signed and that nothing changed afterwards. Every digital signature is an electronic signature; most electronic signatures are not digital signatures.

Not offered here

Dynamic Watermark

A watermark generated at view or download time containing per-recipient details such as a name or timestamp, used to trace leaked documents.

Not offered here

Electronic Signature

A broad legal category covering any electronic mark indicating intent to agree: a typed name, a drawn squiggle, a click on an Accept button. Recognised under frameworks such as ESIGN in the US and eIDAS in the EU.

Try the tool →

Encrypt PDF

The underlying operation behind password protection: scrambling the document's content streams so they are unreadable without the correct key. The PDF standard defines several encryption schemes, and which one applies depends on the PDF version.

Try the tool →

eSign Free

A common search for signing documents electronically without paying for a subscription service.

Try the tool →

Highlight PDF

Marking passages with translucent colour, stored as an annotation layer above the page.

Not offered here

Invisible Signature

A cryptographic signature embedded in the file with no visual mark on the page. It still validates the document's integrity in a reader that checks for it.

Not offered here

Owner Password

The password that controls permissions such as printing and editing. A document can carry an owner password while still opening without any password at all.

Partly covered →

PDF Certificate Sign

Signing a PDF using a digital certificate, producing a signature that readers can cryptographically validate.

Not offered here

PDF Commenter

A tool or reader feature for attaching review comments to specific parts of a document.

Not offered here

PDF Expiry

A rights-management feature that makes a document stop opening after a set date. It requires a DRM system, not standard PDF, and cannot be enforced by the file alone.

Not offered here

PDF Filler

A tool for completing PDF forms, either by filling real interactive form fields or by typing text onto a flat page.

Not offered here

PDF Form Creator

Building interactive fields — text boxes, checkboxes, dropdowns, signature fields — into a PDF so it can be completed on screen.

Not offered here

PDF Form Extractor

Reading the submitted values out of completed PDF forms, typically to collect many responses into a spreadsheet.

Not offered here

PDF Form Filler

Entering data into an existing PDF form's fields and saving the completed document.

Not offered here

PDF Security Remover

A general name for tools that clear password protection and permission restrictions from a PDF.

Not offered here

PDF Security Rights

The permission flags stored inside an encrypted PDF that record which operations are allowed. Note that these are honoured by cooperating readers rather than technically enforced.

Not offered here

PDF Text Stripper

A utility that pulls out just the plain text content of a PDF, discarding all layout and formatting.

Partly covered →

Protect PDF

Applying password security to a PDF so it cannot be opened, or cannot be edited and printed, without the password.

Try the tool →

RC4 Encryption

The older stream cipher used by PDF versions up to 1.5, at 40-bit or 128-bit. The 40-bit variant is considered broken and offers very little real protection today.

Not offered here

Redact PDF

Permanently removing sensitive content so it cannot be recovered. Genuine redaction deletes the underlying text; drawing a black rectangle over it does not, and text hidden that way can usually be copied straight back out.

Not offered here

Remove PDF Password

Stripping a known password from a document so it opens freely afterwards.

Not offered here

Sanitize PDF

Stripping hidden material from a document — metadata, embedded files, scripts, remnants of edited content — before sharing it externally.

Not offered here

Secure PDF View

Displaying a document in a controlled viewer that restricts downloading, printing or copying, typically as part of a managed document platform.

Not offered here

Self-Signed PDF

A document signed with a certificate you generated yourself rather than one from a recognised authority. It proves the file has not changed since signing, but not who you are.

Not offered here

Set PDF Permissions

Choosing what a reader may do with a document — print, copy text, extract pages, fill forms — independently of whether they can open it.

Partly covered →

Sign PDF

Placing a signature onto a document. In practice this covers two quite different things — a drawn image of your handwriting, and a cryptographic digital signature — which are often confused.

Try the tool →

Unlock PDF

Removing password protection or usage restrictions from a PDF. Doing this to your own file with the password you own is routine; doing it to a document you have no rights to is another matter entirely.

Not offered here

User Password

The password required to open a document at all. Without it, the file cannot be read.

Try the tool →

Validate PDF Signature

Checking that a signed document's cryptographic signature is intact and that the signing certificate is trusted and unexpired.

Not offered here

Visible Signature

A signature that appears on the page as a mark you can see and print.

Try the tool →

XFA Forms

Adobe's XML Forms Architecture, a form technology layered on top of PDF that only Adobe's own readers fully support. It has been deprecated in the PDF 2.0 standard.

Not offered here

File formats and technical concepts

Terms describing how PDFs are built internally, and the technology used to process them.

Batch Processing PDF

Applying the same operation to many documents in one run instead of handling each individually.

Partly covered →

Browser Memory Limits

The practical ceiling on how large a file a browser tab can hold and process. It is why a very large PDF may work on a desktop but fail on an older phone.

Try the tool →

Browser Threading

Using workers to move heavy computation off the main thread, so the page stays interactive during long operations.

Try the tool →

Canvas PDF Rendering

Drawing PDF pages onto an HTML canvas element, the technique browser-based PDF viewers use to display and export pages.

Try the tool →

Color Profile PDF

An embedded ICC profile describing exactly how the document's colour values should be interpreted, so colours reproduce consistently across devices.

Not offered here

Linearized PDF

A PDF reorganised so the first page can display before the rest has downloaded, sometimes called fast web view. It matters for large documents served over slow connections.

Not offered here

Memory Safe Processing

Handling files within the browser's sandboxed memory, where a page cannot read another site's data or reach into the operating system.

Try the tool →

OCR

Optical Character Recognition: analysing an image of text and identifying the characters within it, turning a picture of words into words a computer can search, copy and index.

Try the tool →

OCR PDF

Running optical character recognition across a scanned PDF so its contents become selectable text rather than a flat picture.

Try the tool →

PDF Attachment Extractor

Retrieving files embedded inside a PDF container, such as the XML invoice data carried inside a ZUGFeRD or Factur-X document.

Not offered here

PDF Color Space

The colour model a document's content uses — RGB for screens, CMYK for print, or grayscale. Mismatches here are a common cause of print colour surprises.

Not offered here

PDF DPI

Dots per inch: the resolution at which images inside a PDF are stored or at which pages are rendered out. Higher DPI means sharper output and larger files.

Try the tool →

PDF Editor Online

A browser-based tool for modifying PDFs without installing desktop software.

Try the tool →

PDF Extract Images

Pulling the original embedded image files out of a PDF at their stored resolution. This is different from rendering pages to images, which captures the whole page as it appears.

Partly covered →

PDF Font Embedding

Storing the actual font data inside the PDF so text renders identically on machines that do not have that font installed. Without it, readers substitute a different font and the layout shifts.

Not offered here

PDF Generator

Any program that produces PDF files programmatically, from report writers to server-side libraries.

Not offered here

PDF Layer Management

Controlling optional content groups, the named layers a PDF can contain that readers may show or hide independently. Common in CAD and multilingual documents.

Not offered here

PDF Metadata

Information about a document rather than in it: title, author, creation date, producing software and keywords. It is worth checking before sharing files publicly.

Not offered here

PDF Parser

A library that reads a PDF's internal object structure so software can inspect or modify it, rather than just display it.

Not offered here

PDF Reader

Another name for a PDF viewer, sometimes implying extra features like annotation and form filling.

Not offered here

PDF Rendering Engine

The component that turns a PDF's drawing instructions into actual pixels on screen. PDF.js and PDFium are two widely used examples.

Try the tool →

PDF Repair

Attempting to recover a damaged or truncated PDF by rebuilding its cross-reference table and object structure.

Not offered here

PDF Scanner

Software or hardware that captures physical pages and assembles them into a PDF, often with automatic deskewing and OCR built in.

Not offered here

PDF Searchable

A PDF whose text can be found with a search. Digitally created PDFs are searchable by default; scans only become searchable after OCR adds a text layer.

Partly covered →

PDF Structure Tree

The hierarchy of logical elements — headings, paragraphs, lists, tables — that a tagged PDF records to describe its own reading order.

Not offered here

PDF Tagging

Adding that structural markup to a PDF so screen readers can navigate the document in a meaningful order rather than a visual one.

Not offered here

PDF Transparencies

Support for translucency and blend modes in PDF content, which is what allows watermarks to show through underlying text.

Try the tool →

PDF Vector Graphics

Artwork stored as mathematical paths rather than pixels, so it stays perfectly sharp at any zoom level or print size.

Not offered here

PDF Viewer

An application that displays PDF documents. Every modern browser includes one.

Not offered here

PDF/A

The ISO-standardised archival subset of PDF. Everything needed to display the file, especially fonts, must be embedded, and features that could change appearance over time are prohibited. Many government and legal archives require it.

Not offered here

PDF/E

The subset for engineering documents, covering technical drawings and interactive 3D content.

Not offered here

PDF/UA

The accessibility standard for PDF, defining the tagging and structure required for a document to be genuinely usable with assistive technology.

Not offered here

PDF/X

The subset designed for professional print production, with strict rules about colour spaces, embedded fonts and bleed so commercial printers get predictable output.

Not offered here

Print Ready PDF

A file prepared to a commercial printer's requirements — correct colour space, embedded fonts, adequate image resolution and bleed.

Not offered here

Rasterize PDF

Converting vector page content into a grid of pixels. This fixes the appearance exactly but makes text unselectable and quality resolution-dependent.

Try the tool →

Scanned PDF

A PDF whose pages are photographs of paper rather than digital text. It looks like a document but contains no searchable text until OCR is run.

Try the tool →

Text Recognition

The general process behind OCR: matching shapes in an image against known character forms to produce machine-readable text.

Try the tool →

Web Worker

A background thread in the browser. Running file processing in a worker keeps the interface responsive instead of freezing the page while a large document is handled.

Try the tool →

WebAssembly

A binary instruction format that lets compiled languages like C++ and Rust run in the browser at near-native speed. It is what makes heavy work such as OCR practical client-side.

Try the tool →

WebAssembly PDF

PDF processing performed in the browser using WebAssembly modules, so computationally demanding operations run locally instead of on a server.

Try the tool →

Privacy and how browser tools work

Terms describing client-side processing, and what it does and does not guarantee.

Ad-Supported Tool

A free tool funded by advertising rather than by subscriptions or per-file charges.

Try the tool →

Browser Execution

Code running inside the browser's sandbox, with access to what the page holds in memory but not to the wider system.

Try the tool →

Browser Utilities

Small single-purpose tools that run in a browser tab — converters, calculators, formatters and the like.

Try the tool →

Client Side Execution

Running application code in the browser rather than on the server that served the page.

Try the tool →

Client-Side Processing

Performing work in the user's own browser rather than on a remote server. For file tools this is the difference between your document staying on your device and being uploaded to someone else's.

Try the tool →

Client-Side Storage

Browser mechanisms such as localStorage and IndexedDB that let a site keep data on your device between visits. A tool that keeps nothing between sessions does not use these at all.

Not offered here

Cross-Platform Tool

Software that works the same on Windows, macOS, Linux, Android and iOS. Browser-based tools get this almost for free.

Try the tool →

Data Privacy

The broad principle of controlling what happens to information about you and your documents. Note that a site can process files privately while still using ordinary web analytics and advertising — the two are separate questions, and a privacy policy should state both.

Try the tool →

Drag and Drop Interface

Adding files by dragging them onto the page instead of navigating a file picker.

Try the tool →

End-to-End Privacy

In this context, that a document's contents are visible only on your device from start to finish, because they never travel across the network.

Try the tool →

Fast Web Tools

Lightweight browser utilities designed to load and run quickly.

Try the tool →

Free Web Tools

Browser tools available at no cost, commonly supported by advertising rather than subscriptions.

Try the tool →

High-Speed Utility

A tool optimised for quick turnaround. With local processing, speed depends on your own hardware rather than on server load or connection quality.

Try the tool →

In-Browser Utilities

Utilities that do their actual work inside the browser rather than acting as a front end to a server.

Try the tool →

In-Memory Conversion

Converting a file entirely in RAM, with no temporary copy written to disk or to a server.

Try the tool →

Instant Calculation

Producing a result immediately as inputs change, without a page reload or a server request.

Not offered here

Instant File Export

Producing the finished file for download immediately, with no queue and no round trip to a server.

Try the tool →

Lightweight Web App

An application with a small download footprint that loads fast and runs on modest hardware.

Try the tool →

Local Data Retention

Whether a tool keeps anything on your device after you close it. Files held only in page memory disappear when the tab closes.

Try the tool →

Local Processing

Another term for client-side processing: the computation happens on your machine.

Try the tool →

Local Storage Processing

Working with data held in browser storage. Note that this is a different thing from processing a file locally in memory — a tool can do the latter while storing nothing.

Not offered here

Lossless Processing

An operation that preserves the original data exactly. Merging, splitting and rotating PDFs are lossless; compressing images inside one is not.

Try the tool →

Mobile Responsive Utility

An interface that adapts to phone and tablet screens rather than requiring a desktop browser.

Try the tool →

No Server Storage

No copy of your document is stored remotely, because no copy is ever sent.

Try the tool →

No Software Installation

Tools that run in a browser tab with nothing to download, install or update, and no administrator rights required.

Try the tool →

Offline Web App

An application that keeps working without a network connection. This requires a service worker to cache the application files; without one, a page still needs the network to load, even if its tools then run locally.

Not offered here

On-Device Computing

Processing data on the device that holds it instead of sending it elsewhere. The same principle behind on-device speech recognition and photo classification on modern phones.

Try the tool →

Privacy-First Tools

Tools designed so the privacy-protecting option is the default behaviour, not a setting you have to find and enable.

Try the tool →

Private Converter

A conversion tool built so document contents are never exposed to the operator of the service.

Try the tool →

Progressive Web App

A website that can be installed like an app and run offline, using a service worker to cache its own files. A site is only a PWA if it actually ships a service worker and a manifest.

Not offered here

Sandbox Security

The browser's enforced isolation between a web page and both your operating system and other sites, which is what makes running untrusted code in a tab reasonably safe.

Try the tool →

Secure File Processing

Handling documents in a way that limits exposure. Keeping the file on the user's device removes the transmission and storage risks entirely, though it does not replace endpoint security on that device.

Try the tool →

Stateless Web App

An application that keeps no server-side session or stored user state between visits.

Try the tool →

Static Web Tool

A tool served as plain files with no application backend. There is no server-side code that could receive or process your document.

Try the tool →

Web App Optimization

Reducing page weight and deferring non-essential work so a tool becomes usable as quickly as possible.

Try the tool →

Zero Data Retention

Not keeping user data after processing. With client-side tools this is structural: there is nothing to retain because nothing was received.

Try the tool →

Zero Latency

No waiting on network transfer. Processing starts the moment you choose a file, though the operation itself still takes as long as your device needs.

Try the tool →

Zero Server Upload

A design where the file is never transmitted anywhere. The privacy guarantee comes from the architecture rather than from a retention policy you have to trust.

Try the tool →

Zero Tracking

Making no attempt to identify or follow users. Worth distinguishing from private file handling: a site can process documents entirely on-device and still run standard analytics and advertising, which most free tools do.

Not offered here

Zero Upload Converter

A file converter that processes documents locally in the browser instead of uploading them.

Try the tool →
Got a question instead of a term?The FAQ answers 112 of the most common ones.
Read the FAQ →