PDF Studio

Merge, split, reorder, rotate, compress, annotate, sign and convert — eleven operations in one workspace, and your file never leaves this device.

Your file never leaves this device. Open your browser's network panel and watch — nothing is uploaded.

All PDF tools

Eighteen operations, one engine

Each has its own page with instructions and answers. They all open this same workspace with the right mode already selected.

Merge PDF Combine files and drag pages into order. Split PDF Split by range or every N pages. Compress PDF Three quality levels, before/after size. Edit PDF Retype the words on the page. The layout, tables and images are kept. Annotate PDF Highlight, draw, comment and stamp. Sign PDF Draw, type or upload a signature. Rotate PDF Rotate one page or the whole file. Delete Pages Remove pages from a thumbnail grid. Watermark PDF Text or image, opacity and rotation. Add Page Numbers Position, format and start number. PDF to Word Export text and structure to DOCX. PDF to JPG Every page as an image, ZIP for many. PDF to Text Plain text, Markdown or HTML. Images to PDF JPG, PNG or WebP into one document. Word to PDF DOCX in, styled PDF out.
How this works

What a browser can and cannot do to a PDF

PDF Studio is built on two libraries that run entirely on your machine. pdf.js, the renderer Firefox uses to display PDFs, parses your document and draws the page previews. pdf-lib writes the new file. Between them they cover everything on this page, and neither of them has any idea what a server is.

Page-level work — merging, splitting, reordering, rotating, deleting, duplicating, extracting — is exact. The original page objects are copied into the new document untouched, so the text stays selectable, the fonts stay embedded, the links keep working and the file stays the same quality it was. There is no re-encoding step to lose anything in.

Compression is a trade, and we say so

Compressing is different in kind. It renders each page to an image at a lower resolution and rebuilds the document from those images. That is why a 40 MB scan can come out at 3 MB. It is also why the text in the result is no longer selectable or searchable — it is a picture of text now. For a scanned contract you only need to email, that is a good deal. For a document you need to search later, it is not, and the interface says so before you click rather than after.

Where the ceiling actually is

The limit is your device's memory rather than a policy. A 300-page document merges in a couple of seconds on a laptop; the same job on a five-year-old phone takes longer and uses a lot of RAM. Rendering pages to images at 300 dpi is the heaviest thing here — mobile Safari caps total canvas memory and will quietly hand back blank images if you push past it, so the studio frees each canvas the moment it is done with it and warns you before starting something large.

Encrypted files are the one hard stop. A PDF that needs a password to open cannot be opened here at all — the studio will tell you so rather than failing obscurely. Removing a password you already know is on the roadmap and is not built yet, because doing it properly means writing a full PDF security handler and hand-rolled cryptography nobody has reviewed is worse than an absent feature. Removing one you do not know would not be a tool; it would be an attack.