Signature Resizer to 20KB
Many exam and job-application portals ask you to upload a scanned signature under 20KB. This free tool resizes and compresses your signature to hit that limit while keeping it clear and legible. Everything runs in your browser, so your signature is never uploaded.
50% smaller
More options
Used for Make Smaller and Width & Height. Exact KB sets quality automatically.
Private
Image stays in your browser.
Fast
No upload required.
Free
No signup or watermark.
Flexible
Smaller, exact KB, or dimensions.
How to use
- 1
Upload your signature
Click the upload area or drag in a JPG, PNG or WebP scan/photo of your signature.
- 2
Target is preset to 20KB
The 20KB target is already selected. You can switch to 10KB, 50KB or a custom size at any time.
- 3
Fine-tune if needed
Use the width, height and quality controls if you want a specific pixel size. Keep aspect ratio on to avoid stretching.
- 4
Download
Check the final size shown under the preview, then click Download. The file will be a compressed JPG under 20KB.
Why a 20KB signature limit exists
Government exam boards, banks and recruitment portals receive millions of uploads. To keep their storage and bandwidth manageable they cap each signature image — and 20KB is one of the most common limits you will meet for SSC, banking (IBPS/SBI), UPSC and university admission forms. A 20KB JPG is tiny, but a clean black-ink signature on a white background compresses extremely well, so you rarely lose readability.
The problem is that a raw phone photo of your signature is often 2–5 megabytes — hundreds of times too big. This tool bridges that gap automatically so you do not have to fiddle with desktop photo editors.
How the 20KB compression works
When you set a target of 20KB, the tool follows a simple, reliable strategy:
- Reduce quality first. JPG quality is lowered step by step (using a binary search) until the file drops to or below 20KB. Lowering quality removes information your eye barely notices before it removes anything important.
- Then reduce dimensions. If the lowest reasonable quality is still over 20KB — usually because the image is huge — the tool gradually scales the picture down and tries again.
- Warn if impossible. In the rare case a target is physically impossible (for example a 4000×3000 photo squeezed to 5KB at high quality), you will see a friendly message instead of a broken file.
Because signatures are mostly white space and thin dark strokes, hitting 20KB is almost always easy and the result still looks crisp.
Tips for a clean signature scan
- Use a white background. Sign on plain white paper with a black or dark blue pen.
- Light it evenly. Avoid shadows; natural daylight near a window works well.
- Crop tightly. Remove empty paper around the signature before compressing so detail is preserved.
- Avoid re-compressing. Start from the original scan, not a screenshot of a screenshot — each save loses a little quality.
- Match the form rules. If the portal says "JPEG only, 10–20KB, 140×60 px", set those exact values.
Privacy you can trust
Your signature is sensitive — it is a legal mark. That is exactly why this tool runs entirely inside your browser. The moment you pick a file it is loaded into a local canvas in memory; no copy is sent anywhere, there is no account, and refreshing the page erases everything. You can even disconnect from the internet after the page loads and the tool will keep working.
Frequently asked questions
How do I make my signature exactly 20KB?
Upload your signature and the tool automatically lowers JPG quality until the file is at or just under 20KB. If the image is very large it will also reduce the dimensions. You will almost always land slightly under 20KB, which is what forms require ("maximum 20KB").
My signature looks faint after compression. What can I do?
Scan or photograph your signature on white paper with good lighting and dark ink. Before compressing, crop tightly around the signature so the pixels are used for the ink, not empty margins. A tighter crop keeps more detail at the same file size.
What dimensions should a signature be?
Most forms accept roughly 140×60 to 300×80 pixels for a signature. If the form specifies a pixel size, type it into the width and height fields. Otherwise the default works for almost all portals.
Are my photos uploaded to a server?
No. Every step — resizing, cropping and compression — happens locally in your browser using the HTML5 Canvas API. Your image never leaves your device, and nothing is stored or transmitted.
Which output format should I choose?
Choose JPG for photographs and most form uploads because it gives the smallest file size. Use PNG only when you need a transparent background or razor-sharp line art. WebP gives excellent compression but some older government portals do not accept it — check the form requirements first.