PDF Studio

About PDF Studio

PDF Studio is a full PDF editor that runs client-side in the browser. Your documents are never uploaded, with the one exception noted under Scan below.

Workspace and opening: Open PDF loads one or more files from your device in a single pick, and From Vault opens PDFs already stored in your Fias Vault (you pick and approve exactly which documents PDF Studio may read; access is revocable any time under Vault → App Access, and Vault documents over 15 MB must be opened from the device instead) — each open document becomes a tab across the top. Click a tab to switch (every document keeps its own page position and selection); the x closes a tab, asking first when the document has unapplied-to-disk edits (a dot marks edited tabs). All edits live in memory until you press Download or Save to Vault — closing a tab discards its edits. Save to Vault stores the document in your Fias Vault (re-saving updates the same Vault document rather than creating copies), and the Reopen saved menu brings any of them back for further editing in a later session. The Fias AI assistant can also work across tabs for you: opening PDFs from your Vault (via the same approval picker), switching and closing documents, appending one document onto another, copying or moving pages between open documents, and saving one or all documents to your Vault — so batch jobs like opening several Vault files, rotating a page in each, and saving them all back need no further clicks.

Viewing: a thumbnail rail down the left shows every page of the active document with a checkbox for selecting pages; the toolbar has previous/next navigation and zoom from 40% to 300%.

Page operations (View mode, acting on the pages ticked in the rail): Rotate turns the selected pages 90 degrees clockwise and keeps the selection, so pressing it three times gives 270 degrees. Delete removes the selected pages, and cannot delete every page. Extract saves the selected pages as a separate downloaded PDF and leaves the open document untouched. Append PDF merges a second PDF's pages onto the end of the active one. Download saves the active document with every applied edit.

Annotate mode: four tools — Highlight, Box, Text and Draw (freehand) — in five colors (yellow, red, green, blue, black). Drag on the page to draw; with the Text tool, click to place text. Annotations are staged and previewed until you press Apply, which bakes them permanently into the PDF. Clear discards anything staged.

Redact mode: drag black boxes over content to remove, then press Apply Redactions. This is true redaction rather than a cover-up — each affected page is re-rendered as a flat image with the boxes painted in, so the underlying text and content are permanently gone. The trade-off is that redacted pages become images, so their text is no longer selectable or searchable, and the action cannot be undone.

Forms mode: reads the PDF's interactive AcroForm fields and lists them in a side panel. Clicking a field jumps to its page and highlights it in the viewer. You can fill values in, with an option to flatten — flattening writes the values into the page content and removes the interactive fields so they can no longer be edited.

Sign mode (Fill & Sign): draw a signature on the signature pad, then click-drag a rectangle directly on the page to drop it where you want it. The same signature can be placed several times and across multiple pages; Apply bakes the placements in.

Scan mode (OCR): extracts text from pages that have no text layer, such as scans and photographs of documents. Each page is rendered to an image in the browser and sent one page at a time to a Fias platform AI vision model — this is the only feature that leaves your device, and the only one that consumes credits. Two tiers are offered: Fast (cheapest, best on clean text) and Accurate (costs more, better on messy scans). Results can be copied or downloaded as a .txt file.

Encrypted PDFs: a password-protected PDF displays and downloads normally, but all editing features are disabled, because the underlying pdf-lib library cannot safely re-save an encrypted document. Scan/OCR still works on them.

Rendering uses pdf.js; editing uses pdf-lib.

Information

Publisher

jake

Price

Pay as you go

Account

A free Fias account

Version

0.6.1

Updated

August 24, 2026

Works in

Any modern web browser. Add it to your Home Screen to keep it close.