Annotate a PDF online — and fix it while you’re there
Highlight, underline, draw, point, sign, and redact. Then change the wording that’s wrong, instead of highlighting it and asking someone else to.
Open the PDF editorWhat you can mark up
Six tools. Every one draws into the exported PDF, so it opens the same way in any reader — no plugin, no account for the person you send it to.
Highlight
Sweep any line in the colour you want. It snaps to the text, so it reads like a marker pen, not a floating rectangle.
Underline
Pull a clean line under the clause or figure that matters, without touching the words themselves.
Draw freehand
Circle a number, scribble a tick, cross something out. Whatever you would do with a pen on paper.
Arrows & boxes
Point at the thing you are talking about, or frame it. Useful when the note is “this bit, here”.
Signature
Draw, type, or upload a signature and drop it on the line — no printing and rescanning.
Redaction
Remove something for good. Not a black box on top — the text underneath is deleted from the exported file.
A black box is not a redaction
This is the one that catches people out. Drawing a filled rectangle over a name looks exactly like redacting it — on screen they are identical. In the file they are not. The rectangle is just something painted on top; the name is still sitting underneath it, and anyone can select the area and copy the text straight back out. Documents have been leaked this way, repeatedly, by people who thought they had covered something.
If it matters, redact it. The box tool hides things; the redact tool removes them.
Redaction here deletes the underlying content, so the words are gone from the exported PDF rather than concealed. Use the box for pointing at things, and redaction for anything you would not want read.
The annotation you don’t have to make
Most markup exists because the person marking up cannot fix the thing. You highlight the wrong price in yellow, write “should be £4,200” beside it, send it back, and wait for someone with the source file to make the change.
You can skip that here. The text already in the PDF is editable in the same place you are annotating it — click the wrong price and type the right one, with the document’s own font and spacing kept. How that works is worth two minutes if you have only ever annotated PDFs before.
What this doesn’t do
There are no comment threads, no @-mentions, and no reviewer inbox. Markup is drawn on the page, not attached as a conversation beside it. If your job is a multi-day review where several people argue in the margins and resolve each other’s notes, a collaboration platform is the right tool and this is not it.
This is for the other case, which is more common: you have a document, you need to mark it up or clean it up, and you want to send it on in the next five minutes.
Open the PDF editor to mark up your document, or browse the rest of the PDF tools.
Frequently asked questions
You can highlight text in any colour, underline it, draw freehand, and drop arrows or boxes anywhere on the page. You can also sign it, and permanently redact anything private. Everything is drawn onto the page itself, so whoever opens the file sees your markup without needing an account or a plugin.
No — and that is worth being straight about. There are no comment threads, no @-mentions, and no reviewer inbox here. Markup is drawn on the page, not attached as a conversation beside it. If you need a review workflow where several people discuss a document over days, a collaboration platform will serve you better. This is for marking a document up and sending it on.
Yes, and that is the part most annotators cannot do. Elsewhere, spotting a wrong price usually means highlighting it and asking someone else to fix the source. Here you can just change it — the text already in the PDF is editable in the same place you are marking it up, with the original fonts and spacing kept.
No, and the difference matters more than it looks. A black rectangle drawn over a name only hides it visually — the text is still in the file and can be copied straight back out. Redaction here removes the underlying content, so the words are gone from the exported PDF rather than covered up. If you are hiding something that actually matters, use redaction, not a box.
Yes. Your markup is drawn into the exported PDF, so it opens the same way in any reader — Acrobat, a browser, a phone. There is nothing to install on their end and no account for them to create.
No to both. Annotating is free from upload to download, there is no signup, and nothing is stamped onto your page.
Each PDF can be up to 10 MB and 100 pages, which covers most contracts, reports, proposals, and forms. There is no cap on how many documents you mark up.
Mark it up, then send it
Free, no signup, no watermark — and no account needed by whoever opens it.
Open the PDF editor