Annotate PDF

The marks are drawn into the page itself rather than stored as PDF comment annotations. The upside is total consistency: a highlight, underline, strike-out, note marker or freehand stroke looks identical in Acrobat, in Preview, in a browser's built-in viewer, on a phone and on paper, because it is page content like any other graphic. The trade-off is that they behave like ink, not like comments. They do not appear in a reviewer's comments sidebar, cannot be replied to or resolved, carry no author name or timestamp, and cannot be clicked away by whoever receives the file. If your workflow depends on threaded review comments colleagues can answer, a desktop annotator suits better; if you want marks that survive everywhere unchanged, this format is the safer one.

Highlights are drawn as a translucent fill at roughly 32 per cent opacity over the words, so the text underneath stays readable in all five colours. Nothing on the page is removed or rewritten, which means the original text remains selectable, copyable and searchable after saving — a highlighted phrase is still found by a reader's search box. The one thing to know is that the tint sits over the glyphs rather than behind them, so on a very dark background or a heavy scan it reads differently than a highlight in a word processor would. Underlines and strike-outs are drawn as thin coloured lines following the drag you make, and the sticky-note marker is a small coloured tag on the page, not a pop-up holding text.

Colour can be changed afterwards; position and size cannot. Every mark you place appears in the "On this page" list beneath the preview with a colour dropdown beside it, and right-clicking the mark on the page itself opens a small menu carrying Delete and the same five-colour palette. Hovering a row in that list outlines the matching mark on the page, which makes overlapping highlights easy to tell apart. There are no drag handles, so a mark in the wrong place is deleted and redrawn — for highlights and freehand strokes that is genuinely quicker than nudging handles would be. Clear page removes every mark on the current page at once, and the reset control at the bottom of the card starts the whole document over.

Yes — annotation state is held per page across the whole document. The arrows under the preview move between pages, marks reappear whenever you return to a page, and the running totals tell you how many exist on this page and how many across the file. Everything is written in one pass when you press Save annotated PDF, so there is no downloading and re-uploading between pages. Coordinates are stored as fractions of the page rather than as pixels, which is why a mark lands in exactly the spot in the saved file that it occupied in the preview, whatever size the preview happened to be rendered at, and why landscape, rotated and mixed-size pages all map across correctly.

Both the document and every mark you make stay on your device. The PDF is opened by the browser from your disk, each page is rendered locally so you can draw on it, and the marks live in the tab's memory until you save — at which point the annotated copy is written straight to your downloads. Nothing is uploaded and no draft state is synced anywhere, so closing the tab genuinely discards the session instead of leaving a copy somewhere. That matters for what people usually mark up: lease agreements, medical letters, contracts under negotiation, unpublished manuscripts. It also means you can work through a long document with the network disconnected, once the page itself has loaded.

No limit is imposed by the tool: no signup, no quota on marks or pages, and no feature withheld behind a payment — all five tools and all five colours are live from the first click. The realistic ceiling is your device's memory, since the page you are viewing is rendered in the browser and the document is rewritten in memory when you save; a very long file simply takes a little longer at that final step. The download carries your marks and nothing else: no PDFChamp logo, no credit line stamped onto a page, no advertisement buried in the metadata. Its filename gains an -annotated suffix, so the original in your folder is never overwritten.