Signature Crop & Rotate
Phone-camera signatures are often tilted and surrounded by wide empty margins. This tool automatically detects your signature ink, trims the whitespace, and lets you straighten the image - all in one step.
shield_lock🔒 Privacy First: Processed locally in your browser. Files never leave your device.
Upload Signature Image
Upload a scanned or photographed signature. The tool will auto-crop margins and let you straighten the image.
Frequently Asked Questions
How accurate is the auto-crop detection?
The tool scans every pixel in your image and detects non-white ink using a brightness threshold. It finds the exact bounding box of your signature strokes, then adds a configurable padding margin. This works reliably for dark ink (blue, black) on white or light backgrounds. Very faint pencil marks may not be detected.
What image formats are supported for upload?
You can upload JPEG, PNG, and WebP images. These cover all common formats from phone cameras, scanners, and screenshot tools. The output can be downloaded as either JPG (with a white background) or PNG (with a transparent background), depending on your needs.
How does the rotation feature work?
Use the fine rotation slider to adjust from -45° to +45° in 1° increments - perfect for straightening slightly tilted camera captures. Quick-rotate buttons (0°, 90°, 180°, 270°) let you fix signatures that were scanned upside down or sideways. The rotation is applied after auto-cropping for the cleanest result.
Is it safe to upload my signature here?
Absolutely. This tool runs 100% client-side in your web browser using the HTML5 Canvas API. Your signature image is never uploaded to any server - all processing happens locally on your device. You can even disconnect from the internet and the tool will continue to work.