Signature Ink Optimizer
Clean up a photo of your signature: remove the paper, darken the ink and save a transparent PNG.
About this tool
Signature Ink Optimizer turns a phone photo or scan of a handwritten signature into a clean, transparent PNG ready for Sign PDF, Word or email signatures.
Pixels lighter than the threshold become transparent, with soft edges so the strokes stay smooth. Recolour the ink to a uniform blue or black, or keep the original colour and just darken it. The image is trimmed to the signature automatically.
Works with JPG, PNG, WebP, HEIC and more, several images at once, entirely in your browser.
Engines: canvas
How to use
- 1
Add a photo or scan of your signature.
- 2
Adjust the threshold and ink colour.
- 3
Click “Clean signature” and download the PNG.
Use cases
Sign PDFs
Upload the cleaned PNG in Sign PDF for a natural-looking signature.
Email signatures
Add your handwritten signature to an email footer.
Letterheads
Place a transparent signature on documents and certificates.
Frequently asked questions
The background isn't fully removed.
Lower the threshold, or photograph the signature in even light on white paper.
Parts of my signature disappeared.
Raise the threshold so lighter strokes count as ink.
What format is the result?
A PNG with a transparent background.
You may also like
Sign PDF
Draw, type or upload your signature and place it anywhere on the page — free, private and without an account.
Edit & Annotate- Beta
Ink Contrast Booster
Make faded handwriting, pencil notes and old scans dark and readable.
Optimize & Repair Image to PDF
Convert any image — JPG, PNG, WebP, HEIC, TIFF, GIF, BMP, AVIF or SVG — into one PDF.
Convert to PDF