PDF

Also known as: Portable Document Format, PDF file, ISO 32000

PDF (Portable Document Format) is a page-description file format that locks the exact layout, fonts, and graphics of a document so it renders identically on any device — which is why contracts, invoices, bank statements, and forms are almost always shared as PDFs.

Overview

PDF was created by Adobe in 1993 and has been an open ISO standard (ISO 32000) since 2008, so no single vendor owns it. Under the hood a PDF stores text as individually positioned glyphs, vector paths, embedded raster images, and the fonts needed to draw them — that is exactly why the layout is fixed and looks the same everywhere, and also why reflowing the text like a word processor is hard.

There is a crucial distinction between a 'real' PDF and a scanned one. A PDF exported from a word processor or browser has a text layer: the characters are in the file, so you can select, search, copy, and extract them. A scanned PDF is just a stack of page images with no text layer at all — getting words out of it requires OCR first.

PDF is also the file people most often drop into sketchy 'free online' converters, and the format most likely to contain something private: a signed contract, a payslip, a passport scan, an NDA. Browser-only PDF tools sidestep that risk entirely — pages are merged, split, and re-ordered with pdf-lib, rendered to images and read for text with Mozilla's pdf.js, and encrypted or decrypted with AES via the @cantoo/pdf-lib fork, all on your own device. Open DevTools → Network while you work and zero requests fire.

Common questions about PDF

Can I edit a PDF without Adobe Acrobat?

For structural edits — merging, splitting, reordering, rotating, or deleting pages, turning images into a PDF, and adding or removing a password — yes, and it can run entirely in your browser with a library like pdf-lib. Reflowing or rewriting the body text is the hard part, because a PDF stores positioned glyphs rather than editable paragraphs.

What's the difference between a text PDF and a scanned PDF?

A text PDF has an embedded text layer, so you can select, copy, and extract the words directly. A scanned PDF is page images with no text layer — it looks like text to you but is just a picture to the computer, so you need OCR to pull any text out of it.

Are free online PDF tools safe for confidential files?

Most upload your file to their servers to process it, which for a contract, statement, or medical record means handing a sensitive document to a third party. Tools that run in your browser perform the identical operations locally — verify it yourself by opening DevTools → Network and confirming no request fires when you process a file.

Tools that work with PDF

Merge PDF

Combine multiple PDFs into one — reorder by drag, all in your browser.

Split PDF

Extract page ranges or burst a PDF into single pages — in your browser.

Organize PDF Pages

Reorder, rotate and delete PDF pages visually, then export — in-browser.

Images to PDF

Combine JPG and PNG images into a single PDF — in your browser.

PDF to Images

Render each PDF page to a PNG or JPEG — in your browser.

Extract Text from PDF

Pull the selectable text out of a PDF — in your browser.

PDF Password

Add or remove a PDF password (AES) — entirely in your browser.