Signatures for digital forms
Compress Signature to 20 KB
Preset and ready: drop a file and the output lands under 20 KB as JPEG — processed entirely in your browser.
Drop your image here or browse
JPEG, PNG, WebP — everything stays on your device
Why this exact limit matters
Twenty kilobytes is where two signature rules meet: it is the ceiling of the IBPS/SSC band (10–20 KB) and, awkwardly, the floor of UPSC’s signature rule (20–100 KB). One number, opposite directions — IBPS candidates aim just under 20, UPSC candidates must stay just over it. This page is preset to land just below the ceiling, which is the right default for the far larger IBPS/SSC crowd.
A signature is high-contrast line art, which compresses extremely well — hitting a small kilobyte target normally costs almost nothing in legibility. 20 KB is one of the tightest limits you will meet online, and this page is preset to exactly that ceiling.
How to compress to 20 KB
- Drop your signature scan into the box above — it stays on your device.
- Confirm the target: under 20 KB as JPEG.
- The MozJPEG encoder searches its quality range so the JPEG output lands just under your limit. Dimensions are left at their original size unless the target demands otherwise.
- Preview the result, compare it with the original if you want, and download — the filename carries its actual size.
Tip: If your scan has a grey or shaded background, the encoder spends bytes on that noise. A clean white background is the single biggest size saver for signature files.
Measured: a signature-style file against 20 KB
Our signature-style test file (1600×700, dark strokes on white, 22.4 KB from the editor) against a 20 KB ceiling — the encoder barely had to work:
Source file
22.4 KB
1600×700 JPEG
Output
19.8 KB
inside the band
Quality setting
q91
nearly lossless
Resolution
1600×700
unchanged
Quality 91 means the signature is visually identical to the source — that is how much headroom line art has. A 20 KB budget only gets difficult when the scan carries grey shadows or a photographed background; a clean scan clears it at near-max quality every time.
Signature rules that meet at 20 KB
| Form | Photo size rule | Dimensions | Format |
|---|---|---|---|
| IBPS PO & Clerk | 10–20 KB — 20 is the ceiling | 140×60 px | JPG |
| SSC CGL | 10–20 KB | 236×79 px | JPG |
| SSC CHSL | 10–20 KB | 200×80 px | JPG |
| UPSC exams | 20–100 KB — 20 is the floor, aim above it | 350–500 px wide | JPG |
From the 2025–26 cycles. If your form is UPSC, set the target above 20 KB (its own page caps at 100) instead of using this preset as-is.
Frequently asked questions
I am applying to UPSC — is this preset wrong for me?
Use it consciously: this page aims just under 20 KB, while UPSC requires signatures above 20 KB. Set a target like 50 KB for UPSC instead; the encoder maximizes quality up to that ceiling and you clear the floor with margin.
Why is my signature file bigger than my photo after compression?
Usually it is not — line art compresses far better than faces. If yours is bigger, the scan has noise: grey background, JPEG artifacts from a phone screenshot, or a border of desk around the paper. Crop tighter and clean the background.
Does the 140×60 pixel rule matter as much as the KB rule?
Both are enforced. IBPS checks dimensions and size independently — a 15 KB signature at 800×400 fails the dimension check. The preset page for 140×60 locks both constraints at once.
How do I scan my signature in the first place?
Sign on plain white paper, photograph it in even daylight, crop tightly around the signature, and bring it here. Crop first — everything that is not signature is wasted bytes.
How does the tool hit the exact JPEG size?
It encodes your image with the MozJPEG encoder several times, binary-searching the quality setting until the output lands just under your limit — then keeps that best result.
What happens to my image when I close the tab?
It is discarded from memory. Nothing was transmitted and nothing was stored, so there is nothing to delete.