✓ Check any box
Real form fields and plain printed squares alike — MegaPDF recognizes drawn checkboxes that other apps treat as decoration.
Free & Open Source
Someone sent you a PDF. Send it back done.
Open. Fix. Save. Done.
MegaPDF does the one job most people actually have with a PDF: check the boxes, drop in your signature, and save it back — without an account, a subscription, or your document ever leaving your device.
Highlighted features
What MegaPDF does today, not a log of what changed to get here.
T Type on any line
Tap or click where the answer goes and type it. Pick the size and the face so it matches the form you are filling in — then drag it into place, or open it again to fix a typo.
✏ Fix the document's own text
Wrong date? Misspelled name? Tap or click the line and retype it. MegaPDF keeps the document's own font where it can, says so when it had to use a similar one, and Undo puts the original back exactly. It stays layout-safe on a very wide range of edits: a 22,000-edit test run found none that disturbed the page.
■ Redact, and it really is gone
Mark what has to come out — a name, an address, a picture — and MegaPDF takes it out of the file rather than covering it over. What was underneath is gone: no other app can copy it or search for it. Whiteout (Cover on the Mac) still only covers, and says so. A mark can be selected, moved, reshaped and removed before you save — one drag is one undo step, Clear all marks drops every mark at once, and a mark never outlives the document it was made on.
✎ Sign like you mean it
Draw your signature, type it, or use a photo of the one on paper — the white background disappears. Place it, move it, resize it until it sits right on the line.
◐ Reading mode
One tap or click takes the toolbars — and the side pane on the desktops — off the screen and leaves the page. A small bar carries the page number and the way back. Page colours sit beside it: Normal, Sepia for a long read, or Night for a dark room — and Open documents in reading mode starts every one that way.
⊞ Page tools
A Pages pane puts the document's pages in front of you: rotate one that was scanned sideways, delete it, drag pages into a different order, insert a blank page or another PDF's pages, or save the pages you picked as a file of their own. Each is one step in the undo history.
⊕ Zoom where you're looking
Zoom holds the point you're pointing at instead of the corner of the page, however you ask for it — the menu, the keyboard, a pinch, or the wheel.
⧉ Tabs
On Windows, Mac and Linux, a second PDF opens in a tab beside the first, in the same window — from Open, from a file dropped on the window, or from a double-click in the file manager, which lands in the window you already have. Each tab keeps its own undo, find and zoom, and closing asks about each document that needs saving.
↗ Open with, and Share
On iPhone, iPad and Android, MegaPDF is a PDF viewer: open a PDF from Files, Mail, Drive or any app's share sheet straight into it, and send it back with Share. With unsaved changes, it asks — Save, Share without saving, or Cancel.
M↓ Export as Markdown
Save As (Export as Markdown on Android, iPhone and iPad) writes
the document's text as a Markdown file: headings,
paragraphs, lists and the values you filled in. An export, not a
save — the PDF is untouched. The same text comes out of a
terminal with megapdf-cli extract, on Linux, Windows
and Mac.
💾 Save without fear
Every save is verified before it touches your original, so a failed write can never corrupt the file someone sent you.
🔍 Find any word
Search the whole document as you type. Every match lights up, the counter tells you how many, and one tap or Enter walks you to the next.
🔑 Protected PDFs
Open one with its password. If its owner restricted what may be changed, MegaPDF respects that and says so, and the owner password unlocks it. Set a password on a document, change it, or remove it.
XL Very large PDFs
A 2.5 GB file opens straight away, without using gigabytes of memory. Banner-size pages measure at their real size, and pages full of pictures draw several times faster.
▤ One toolbar, fit to the platform
On Windows, Mac and Linux, the toolbar is a single row, with pickers appearing beside the tool they belong to and everything else under More. On iPad, the everyday tools sit in a wide row of their own under the navigation bar, each with its title beside its icon.
🔒 Private by design
No permissions to grant, no network access, no analytics. There is no server for your documents to go to — and the code is open, so anyone can check. In English and in French, following your device.
See it in action
The real app, doing the real job — no mockups.
One engine, five platforms. Documents you sign on Windows
open perfectly on a Mac, an iPhone, an iPad, Android or Linux — and
vice versa.
Windows 11 · macOS · iOS / iPadOS · Android · Linux
Something not working? The support page answers the things
people ask most — and helps you write to us about anything it
doesn't. One person reads those messages, and nothing you type on
that page is sent anywhere until you send it yourself.
Support