Upload signature
Upload a JPG, PNG, WebP, HEIC, or HEIF image of your signature.
Free · private · no upload
JPG · PNG · WEBP · HEIC10KB–50KB+RUNS LOCALLY
Upload or drop signature here
or
JPGPNGWEBPHEIC20KB
Your signature is processed in your browser. Nothing is uploaded.
Common signature size targets
Form Tools
Signature Resizer Online with Clean Background
Resize your signature to exact sizes like 10KB, 20KB, 30KB, or 50KB. Clean the paper background, crop the signature area, darken the ink, set form-ready dimensions or keep the original size, and preview the result before downloading. Everything runs in your browser, so your signature never leaves your device.
How to Convert, Clean, Crop, and Resize a Signature
Crop if needed
Use Manual crop to keep only the signature and remove nearby paper or shadows.
Clean background
Use Clean Signature to whiten the paper background and darken the ink.
Trim blank space
Keep auto-trim enabled to remove extra paper around the signature.
Set size
Choose a target like 20KB, then use None, a preset, or custom dimensions.
Preview in form
Check the resized signature inside a sample application form box.
Download
Download the final signature file for your exam, job, visa, or government form.
Why This Signature Resizer Is Different
Most signature tools only compress an image. This tool is built for real exam, job, visa, and government form requirements where the signature also needs a clean white background, readable ink, correct crop, exact file size, and a form-ready preview.
Clean Signature
Whiten gray paper, reduce shadows, and darken weak ink before compression.
Manual Crop
Select the exact signature area, then move or resize the crop box before processing.
Auto-Trim
Remove extra blank paper around the signature without stretching the final image.
Exact KB Target
Resize signatures for strict limits such as 10KB, 20KB, 30KB, or 50KB.
iPhone HEIC Support
Convert HEIC and HEIF signature photos in the browser before resizing.
Form Preview
See how the resized signature may look inside an application form box.
Private Processing
Canvas cleanup, resizing, and compression run locally in your browser.
Definitions
Resize Signature to 20KB Online
Many exam portals, scholarship forms, job applications, and government websites ask for a signature under 20KB. This signature resizer lets you set a strict target file size and download a JPG, PNG, or WebP output that is close to the selected KB limit.
If your form only mentions file size, keep Signature presets set to None. If your form gives a width and height, choose a preset such as 140 x 60 px or 300 x 100 px, or enter a custom size.
Common Requirements
Signature Size 10KB to 20KB and 4KB to 30KB
Some upload forms ask for a fixed limit like 20KB, while others mention a range such as 10KB to 20KB or 4KB to 30KB. In those cases, start with a middle target like 20KB so the ink stays readable, then lower the target only if the portal requires a smaller file.
If the instruction says the signature must be scanned on white paper with blue or black ink, use Clean Signature, keep auto-trim enabled, and choose JPG unless the form specifically asks for PNG. This keeps the signature easier to read while still fitting a strict KB limit.
Why It Matters
Clean Signature Background Before Resizing
A signature photo often has gray paper, shadows, or weak ink because it was captured with a phone camera. The Clean Signature option uses browser-based canvas processing to make the background white and the signature darker before resizing.
This is useful for exam forms, job portals, visa applications, and government websites that reject unclear or dark signature uploads. If your form needs a strict file size, start with the 20KB resizer requirement and use this signature tool for the final form-ready file.
Crop Control
Crop Signature Online Before Compression
Manual crop is useful when the photo includes extra paper, table edges, shadows, or another mark near the signature. You can draw a crop box around the signature, then adjust the sides or corners before resizing. Auto-trim can then remove remaining blank space around the selected area.
iPhone Photos
Convert HEIC Signature Photos from iPhone
iPhone photos are often saved as HEIC or HEIF. This page can convert a HEIC signature photo in the browser, clean it, and resize it to the required KB size. That means you do not need a separate HEIC converter before preparing your signature upload.
Form Preview
Preview Your Signature in a Sample Form
After resizing, the tool shows your output inside a sample application form signature box. This helps you check whether the signature looks clear, centered, and readable before uploading it to the real form.
Privacy
Private Browser-Based Signature Processing
Signature cleanup, HEIC conversion, cropping, trimming, resizing, and compression run with client-side JavaScript and the browser Canvas API. Your image is processed on your device instead of being uploaded to a server.
Local testing notes
Tested for real form requirements
We test JPG, PNG, WebP, HEIC, and HEIF signatures for file-size accuracy, dimensions, background cleanup, crop results, auto-trim, and form preview. Built and tested by Mozammel Hoshen Chowdhury. Review process: Editorial Policy.
Frequently Asked Questions
Can I resize my signature to 20KB?
Yes. Upload your signature image, choose the 20KB preset, pick the required dimensions, and download the resized signature.
Can I resize a signature from 10KB to 20KB?
Yes. Use the 10KB or 20KB target preset depending on your form requirement. If the portal accepts a range, start with 20KB for clearer ink and lower the target only if the upload is rejected.
What does 4KB to 30KB signature size mean?
It means the final signature file must be at least 4KB and no larger than 30KB. Start with the 20KB preset, keep JPG selected for broad compatibility, and use crop or auto-trim to remove extra blank paper.
Can this tool make the signature background white?
Yes. Turn on Clean Signature to make gray, yellow, or shadowed paper backgrounds white and darken the signature ink with browser-based canvas processing.
Can I crop my signature manually before resizing?
Yes. Use Manual crop to select only the signature area. You can move and resize the crop box before processing, so you do not need to redraw it from scratch.
Can I crop a signature online and then resize it in KB?
Yes. Upload the signature, turn on Manual crop, select the signature area, and then resize the cropped output to a target such as 10KB, 20KB, 30KB, or 50KB.
Can I resize a HEIC signature photo from iPhone?
Yes. The tool supports HEIC and HEIF images and converts them in your browser before cleaning, cropping, and resizing.
Can I resize without forcing signature dimensions?
Yes. Keep Signature presets set to None if your form only asks for a file size such as 20KB and does not require a fixed width and height.
Is my signature uploaded to a server?
No. Signature cleanup, trimming, cropping, resizing, and compression run in your browser. Your signature stays on your device.
Which dimensions should I use for an exam signature?
Many exam forms use small boxes such as 140 x 60 px, while larger forms may use 300 x 100 px. Always follow the exact requirement from your form if it provides one.
Will the tool stretch my signature?
No. The signature is fitted inside the selected box with a white background, so it keeps its shape instead of being stretched.