Where a 20 KB limit comes from
20 KB is the classic limit for signature and photo fields on government application portals — exam registrations, visa forms, bank KYC, university admissions. These systems were built for dial-up-era file sizes and reject anything larger with an unhelpful error.
Getting a modern 4 MB phone photo under 20 KB by hand means guessing at quality settings and dimensions repeatedly. This tool automates it: it binary-searches the quality level, and only reduces dimensions when quality alone can't reach the target.
What fits in 20 KB — honest expectations
| Content | Realistic result at ≤20 KB |
|---|---|
| Signature on white background | Excellent — crisp at 600 px wide |
| Passport-style headshot | Good at ~300–400 px — exactly what portals expect |
| Document scan (1 page) | Readable at reduced size; consider 50–100 KB if allowed |
| Detailed landscape photo | Small dimensions, visible softness — unavoidable at this size |
Portal tip: most forms that demand ≤20 KB also specify dimensions (e.g. 140×60 for signatures, 200×230 for photos). Crop to the required shape first, then compress here — the size target will be easy to hit at high quality.