Screenshot Annotator
Drop in a screenshot, draw arrows, boxes, freehand marks, and text, blur out anything private, then download.
Click to choose a screenshot, or drag and drop it here
Stays on your device, nothing is uploaded.
How it works
Every annotation, arrow, box, freehand stroke, text label, or blur region, is stored as a lightweight shape object rather than baked directly into pixels as you draw. On every change the base screenshot is redrawn first, then all shapes replay on top in order, which is what makes undo/redo work: it just trims or replays that shape list. Blur regions are the one exception that touches pixels directly, they sample and average a grid of blocks over the selected area (a simple box blur) so the underlying detail is genuinely destroyed in the exported file, not just visually covered.
The download is a direct PNG export from the canvas via toBlob. The image
never leaves your browser at any point, which matters since screenshots frequently contain
private information.
Common questions
What's the blur/redact tool for?
Drag it over anything you want hidden, an email address, an account number, a face, and that region is permanently pixelated in the exported image. It's applied to the actual pixel data, not a CSS overlay, so it can't be peeled off in an image editor.
Can I undo a mistake?
Yes, every shape you draw is a separate step, and Undo/Redo walks back and forward through that history. Nothing is baked into the image until you download it.
Is my screenshot uploaded anywhere?
No. Everything, drawing, blurring, and export, happens in your browser on an in-memory canvas. Nothing is uploaded, which matters given screenshots often contain private information.