Signature Resizer
Resize a scanned or photographed signature to the pixels and KB limit your form specifies, with an optional clean-up that turns a grey paper background white.
Drag and drop a file here, or
JPG/JPEG, PNG · up to 25 MB per file
Your image is processed entirely inside your browser using the built-in canvas feature. It is not uploaded to CentralMirror or anyone else, and it is discarded when you close or leave the page. Privacy policy
How to use the Signature Resizer
- 1Sign in dark ink on plain white paper and take a clear, well-lit photo or scan.
- 2Crop it tightly around the signature with the Image Cropper if there is a lot of empty space.
- 3Upload it here, enter the required width, height and maximum KB from your form.
- 4Turn on "Whiten background" if the paper looks grey, adjust the strength, then click Resize and download.
Supported formats and limits
- Input: JPG/JPEG and PNG (WebP where noted).
- Maximum file size: 25 MB per image.
- Maximum resolution: 40 megapixels (for example 8000 × 5000 px), to avoid running out of memory on phones.
- Camera rotation (EXIF orientation) is applied automatically; other metadata such as GPS location is removed from the output.
- Output: JPG.
Tips for a clear signature image
Use a black or dark blue pen and sign larger than usual so the strokes stay visible after resizing to a small size. Photograph straight from above in daylight to avoid shadows.
The "Whiten background" option makes every pixel lighter than the chosen level pure white. Increase the strength if the background still looks grey; decrease it if thin parts of your signature start to disappear.
Sizes are shown in KB where 1 KB = 1024 bytes, which is how most upload forms measure files. If a form says "between 10 KB and 50 KB", aim for a target a little below the upper limit and check the minimum too.
As with photos, use the exact dimensions from your official notification. CentralMirror's sizes are common examples only.
Frequently asked questions
How do I reduce my signature to 10 KB or 20 KB?
Enter the required pixel size, type 10 or 20 in the maximum KB box and click Resize. Signatures are small and mostly white, so they usually reach these limits easily at good quality.
My signature looks faint after resizing. What can I do?
Lower the "Whiten background" strength, sign again with a thicker pen, or crop more tightly so the signature fills more of the image before resizing.
Is my signature stored anywhere?
No. Processing happens in your browser and nothing is uploaded or saved by CentralMirror.
Can I make the background transparent?
Not with this tool. Online forms almost always require JPG, which does not support transparency, so the background is made white instead.