Browser-based image workflow
Screenshot Annotator
Arrows, numbered labels, rectangles and opaque region masking.
Settings
Choose an image to begin.
Privacy: This published tool does not upload your selected files. Photos remain within this browser session unless you explicitly download an export. Large images may use significant device memory.
How to use Screenshot Annotator
- Select a supported source image from your device.
- Adjust the options and, for drawing tools, place annotations directly on the canvas.
- Select Process locally, inspect the output or its manifest, and download your results.
What this tool does
Mark up screenshots with arrow strokes, text and flattened black redactions. Mark up screenshots with arrow strokes, text and flattened black redactions.
Limitations
Annotations are static, not semantic. Verify redaction covers every sensitive region.
Decoded images are limited to 30 megapixels and 16,384 pixels per side; larger raster workflows can exceed browser memory even below these limits. Files must be 20 MB or smaller each and selection must be at most 120 MB. Animated inputs are rendered as a still frame; browser decoder capabilities differ. No paid APIs or server-side image upload endpoints are used.
Discover other image workflows or review our processing privacy notes.