Professional PDF Editor
Annotate, sign and redact a PDF in your browser. The file is opened, edited and saved on this device.
Upload PDF Document
Drag & drop or click to browse
What The Editor Gives You
Seven Tools On One Overlay
Select, Text, Freehand Draw, Highlight, Rectangle, Circle and Redact, plus Add Image. Everything you place sits on an editable layer above the page and can be moved, resized, recoloured or deleted until you download.
Properties Follow The Selection
The right panel tracks the active tool and whatever you click: eight swatches plus a colour picker, font size 8 to 72, brush size 1 to 50, border width up to 20, highlight opacity 10 to 100 per cent.
Undo Per Page, Fifty Deep
Each page keeps its own history, up to fifty snapshots or eight megabytes. A burst of typing collapses into one entry, and Delete or Backspace removes the selection.
Untouched Pages Are Copied, Not Rebuilt
Only pages carrying annotations are rewritten on save. The rest are copied from the original, so their text stays selectable and their quality is unchanged.
Redaction Removes Rather Than Covers
A redaction box replaces its page with a flat 150 DPI image of the page plus your boxes, so the text underneath is gone from the file rather than hidden behind something.
Nothing Leaves This Tab
pdf.js draws the pages, pdf-lib writes the result, both in your browser. No upload, no server round trip, and it keeps working offline once loaded.
How This PDF Editor Works
Drop a PDF on the panel above and pdf.js parses it in the page. Each sheet becomes a page object: the left column renders thumbnails from the top, one at a time, and the main area draws every page onto a canvas with a transparent editing layer stacked over it. Zoom runs from 50 to 300 per cent in ten-point steps, applied instantly as a CSS transform and re-rasterised 300 milliseconds after you stop clicking, so the page stays sharp without a full re-render on every press.
Long documents render as a moving window. Only pages within about 1,200 pixels of the viewport hold a bitmap; scroll past one and its raster, plus the backing store of the two canvases behind it, is released and rebuilt when it comes back. Annotations, layout and undo history all survive, because only pixels are discarded. A single page raster is capped at four million pixels, device pixel ratio at two, and pages are rasterised one at a time through a queue, so a few hundred pages stay workable.
Clicking with the Text tool puts a caret where you clicked; type and the box stays, click away without typing and it is dropped. Rectangle and Circle place a starter shape you drag and resize by its handles. Draw and Highlight are brush modes, the highlight carrying an alpha value from the opacity slider. Add Image scales a picture to 200 pixels wide and centres it on the page you are looking at — the page with the most pixels on screen, which is also the page Undo and Redo act on.
Download rebuilds the file with pdf-lib from the original bytes, not from what is on screen. A page annotated but not redacted has its overlay exported as a transparent PNG at 150 DPI and stamped over the untouched original; a page holding a redaction box is replaced by a flat image instead. Rotated pages are anchored to the corner their rotation maps to and measured from the CropBox, which is what a viewer uses. The result arrives as edited-yourfile.pdf, or secured-yourfile.pdf when anything was redacted.
What it will not do: rewrite the text already in the document, or change its structure. A PDF holds positioned glyphs in subset fonts rather than paragraphs, so cover the old text with a white rectangle and type over it. Pages cannot be added, deleted, reordered or rotated here, and typing into a form draws on top of the field rather than filling it.