Where a 20 KB limit comes from
A 20 KB limit almost always means one thing: a signature upload. Exam and recruitment portals store hundreds of thousands of applications, so they keep the signature file tiny. Many also use 20 KB as the minimum for the photo, which is why people searching for “20 KB” are often filling in two boxes on the same form.
These are limits we checked in official notices. They change from one notice to the next, so always read the one for your exam.
| Who asks | What | File size | Size in pixels or cm |
|---|---|---|---|
| IBPS (India) bank exams | Signature | 10–20 KB | 140 × 60 px (preferred) |
| SSC (India) exams | Signature | 10–20 KB, JPEG | about 6.0 × 2.0 cm |
| IBPS, UPSC (India) | Photograph | at least 20 KB | 20–50 KB and 20–200 KB maximum |
Sources: IBPS scanning guidelines published with each recruitment notice on ibps.in; SSC notice of examination for the CAPF Sub-Inspector exam 2026, para 8.6, on ssc.gov.in; and UPSC’s instructions for uploading the photo and signature.
How this page gets you under 20 KB
This page is the Compress Image to KB engine locked to 20 KB. For each file it:
- tries a high JPG quality and measures the real file,
- searches down the quality scale until the file is as close to 20,000 bytes as possible without going over,
- if even a low quality is too big, shrinks the pixel size just enough and tries again.
The result is a JPG of 20,000 bytes or less. That is stricter than 20 × 1,024 = 20,480 bytes, so it passes whichever way the portal counts a kilobyte.
Worked example
We ran a 1920 × 1200 photo of 420 KB through the engine with a 20 KB target. It came out at 19.4 KB, quality 48, 1048 × 655 pixels. Squeezing all 2.3 million pixels into 20 KB would have needed a quality so low that the photo turned into blocks, so the tool kept a reasonable quality and used fewer pixels instead.
Signatures are much easier. A signature is mostly white paper with a few dark strokes, which JPG compresses very well. A cropped signature around 600 × 200 pixels typically fits under 20 KB at high quality, and at the 140 × 60 pixels IBPS prefers it is far below the limit.
Making a signature that passes first time
- Sign in black ink on plain white, unlined paper. Most notices ask for black ink, and capital letters are often not accepted as a signature.
- Photograph it in daylight, phone held flat above the paper, with no shadow from your hand or phone.
- Crop tightly around the signature with Crop Image. If the form gives a size such as 140 × 60 pixels, crop to that shape (7 : 3) and enter 140 and 60 as max width and height here.
- Compress it here and check the file size shown in the list.
When the file is too small
Forms with a 10–20 KB range reject files under 10 KB. A tiny, tightly cropped signature can fall below that because there is so little in it. If that happens:
- crop with a little more white space around the signature,
- use a larger photo of the signature (do not reduce it first),
- or leave the max width and height empty so the tool keeps more pixels.
The tool always aims as close to 20 KB as it can, so with enough pixels it lands in the 10–20 KB window.
Tips
- One photo, two limits? For a photo with a 20–50 KB range, use Compress Image to 50 KB instead; aiming at 20 KB would risk falling under the minimum.
- UPSC asks for three signatures one below the other, between 20 and 100 KB, so this page is too small for it. Use the UPSC Photo Resizer, which also prepares the photo.
- SSC applicants: the application captures a live photo, so only the signature is uploaded. The SSC Photo Resizer sizes it to the 6 × 2 cm shape.
- Privacy: signatures are sensitive. Here they are processed on your device and never uploaded.