Free PDF tools that never upload your files

What a browser-based PDF toolkit means in practice

For the last fifteen years, PDF tools have worked one way: you upload a file to someone else’s computer, they process it, you download the result. That model made sense when browsers were slow and JavaScript could not manipulate binary data. It makes much less sense now.

Modern browsers can read and write PDF files directly. Mozilla’s PDF.js — the same engine Firefox uses to display PDFs — renders a page onto a canvas in milliseconds. pdf-lib writes valid PDF structures in pure JavaScript. JSZip packs dozens of files into a ZIP inside the tab. And WebAssembly brings compiled C and Python code into the browser at near-native speed, which is how the password tools here can run real AES encryption without a server.

Put together, that toolkit can do almost everything a desktop PDF application does, without your file ever crossing a network boundary. The only thing genuinely given up is scale: your device does the work, so a 900 MB document is a bad idea, whereas a server farm would handle it. For real documents — forms, statements, certificates, reports, photos — that trade is a clear win.

The 27 tools, grouped by what they do

Merge and split. Combine several PDFs into one, break one into many, reorganise pages by dragging thumbnails, delete pages you do not want, or extract just the section you need.

Compress. Four quality levels plus two dedicated targets: 100 KB and 200 KB, for portals with hard upload limits.

Convert to PDF. JPG photos, mixed images, iPhone HEIC photos, plain text and HTML — all becoming proper PDFs with your page size and margins.

Convert from PDF. Pages out as JPG or PNG, the text layer out as a .txt file, and every embedded picture out as a ZIP of original-resolution images.

Edit and sign. Rotate pages permanently, add page numbers in eight formats, watermark with text or a logo, crop margins, resize to A4 or Letter, convert to grayscale, and sign with a drawn, typed or uploaded signature.

Security. Real AES password encryption, and removal of a password you already know from your own documents.

A note on big files, and what to do instead

Because your own device does the work, the practical limits are your device’s. A 300 MB PDF may not fit in a browser tab’s memory on a laptop with 4 GB of RAM, and it definitely will not on a phone. The tools warn above 100 MB and block above 300 MB on desktop and 150 MB on mobile, with a plain explanation rather than a mysterious failure.

The good news is that large PDFs are usually large for one avoidable reason: high-resolution colour scans. Compressing first, or converting to grayscale, typically turns a 40 MB document into a 1 MB one — after which everything else is fast and comfortable.

If you regularly handle genuinely enormous documents, a desktop application is the right tool and we would rather say so than have you fight the browser. For the documents people actually send each other, the browser is faster, more private and just as capable.

How to use this site well

Start from the original file each time. Compressing an already-compressed PDF, or re-exporting an image for the third time, loses quality permanently. Keep your master file, and run each operation from it.

Match the tool to the limit. If a portal says 200 KB, use the 200 KB tool rather than the general compressor — it searches for the best quality that fits instead of making you guess a level.

Check the result before uploading. Open the downloaded file, zoom to 100%, and confirm that names, numbers and seals are readable. Ten seconds of checking prevents the most avoidable rejections.

Bookmark the pages you will reuse. Most people need two or three tools repeatedly and nothing else. Bookmark those, and the rest of the site is there when an unusual job comes along.

Keep sensitive documents private. That is the whole point of building it this way. Your salary slip, your Aadhaar and your bank statement should never be uploaded to a website, and here they are not.