Signature resizer
Resize a photo of your signature for an online application: the paper is cleaned to white, the empty margins are trimmed, and the result is a JPG at the pixels and KB the form asks for. Nothing is uploaded.
Free · Runs in your browser · Updated 17 October 2026
Signature resizer
Settings
The file will be at most this size. 1 KB = 1,000 bytes, so it also passes forms that count 1,024.
Optional. Leave both empty to keep the size; fill one to keep the shape; fill both for an exact size a form asks for (the picture is centred and trimmed to that shape, never stretched).
How to
Resize a signature for a form.
- 1Sign in black or dark blue ink on plain white paper and take a well-lit photo or scan, straight on.
- 2Open the photo here. Type the pixel size the form asks for (for example 140 × 60) and its KB limit (often 10KB or 20KB).
- 3Check the preview, adjust the paper cut-off if faint strokes vanish or shadows stay, and download the JPG.
What it does
Three fixes forms care about.
- White background. Phone photos of paper come out grey or shadowed. Every pixel lighter than the cut-off becomes pure white; the ink is kept.
- Tight crop. Empty paper around the signature is trimmed, leaving a small border, so the signature fills the box the form shows.
- Exact size and KB. With both width and height filled, the result is exactly that size (centred, never stretched) and at or under the KB limit.
Before you upload
Check the form’s own notice.
Each form sets its own rules: pixel size, KB range, JPG only, and sometimes ink colour. Follow those; this tool just makes them easy to meet. For the photo that goes with it, use the 20KB resizer or 50KB compressor.
FAQ
Questions people ask first.
- How do I resize my signature to 20KB?
- Open a photo or scan of the signature in the tool above, leave the target at 20KB (or type 10 for 10KB), add the pixel size if the form gives one, and download the JPG.
- What size should a signature be for an online form?
- Whatever the form’s notice says; common requests are about 140 × 60 pixels and 10KB to 20KB as a JPG. Type those numbers in Width, Height and Target size.
- How do I make the signature background white?
- Keep “Clean the background” on. If grey shadows remain, lower the paper cut-off; if thin strokes disappear, raise it.
- Can I take the photo with my phone?
- Yes. Sign on white paper, photograph it in daylight without your shadow over it, and keep the phone parallel to the paper. iPhone HEIC photos work too.
- Is my image uploaded?
- No. The image is opened, compressed and saved by your own browser. Nothing is sent to Daniotech or any other server, and the tool keeps working offline once the page has loaded.
Related
More free tools.
- Resize image to 20KBGet a photo or signature under 20KB for an application form, at the best quality that fits, with optional exact pixels.
- Compress image to 10KBSqueeze a photo or signature under 10KB for strict upload forms, at the best quality that still fits.
- Black and white photo converterTurn a colour photo into black and white (greyscale) or pure two-tone black and white.
- Compress image to 50KBShrink a JPG, PNG or phone photo to under 50KB, or any size you type, in one step. Batch and ZIP download.
From the team behind the tools
Need image handling inside your own app?
Daniotech builds web and mobile products, including upload flows that resize, convert and check images on the device before they reach your server.