Compress Image to 20KB Online

Yes. SSC (CGL, CHSL, GD and Selection Post notifications) and IBPS (PO, Clerk, RRB) both publish 10–20KB as the accepted signature file size, in JPG/JPEG format. 20KB sits right at the upper edge of that window, so it is the safest choice if you want maximum clarity without breaching the limit.

Most SSC and IBPS application portals hard-block uploads above 20KB with a JavaScript file-size check, so the form simply won't accept it. Use our tool to bring it down to exactly 20KB or slightly under, rather than guessing with a generic compressor.

No. Photo and signature fields have separate dimension requirements (a signature is a wide, short rectangle; a photo is a portrait). Compress each scan separately using the correct crop, and use our 20KB tool for the signature box specifically.

At very small sizes, JPG compression can lighten faint pencil or grey-ink strokes. Re-scan your signature with a black or dark-blue ink pen on plain white paper before compressing — this preserves contrast far better than trying to fix a faint scan after the fact.

Our tool treats 1KB as 1,024 bytes (the binary definition computers actually use), so choosing 20KB targets a file of at most 20,480 bytes. A small number of strict portals count 1KB as exactly 1,000 bytes instead; in that rare case, aim slightly under 20KB to be safe.

At 20KB, expect quality that is soft and noticeably lower-detail. Our tool always reduces quality gradually first and only shrinks pixel dimensions if quality reduction alone can't reach 20KB, which keeps the result looking as sharp as possible for this target.

For a 20KB target, our tool almost always needs its pixel dimensions reduced as well as quality, since 20KB leaves very little room for a full-size photo. You generally don't need to resize manually first — the binary-search engine tries quality reduction before touching dimensions, since that usually preserves more visible detail than shrinking the image outright.

You can upload JPG, PNG, WebP, AVIF, GIF, or BMP and compress to 20KB. For output, choose Auto (the tool picks the best format for a 20KB target) or force JPG, PNG, WebP, or AVIF specifically using the Output Format dropdown.

No. Compressing to 20KB happens entirely inside your browser using the HTML5 Canvas API — nothing is ever sent to a server. That matters especially for a signature or small ID photo, which you may not want leaving your device at all.

Not currently — this 20KB tool processes one image at a time so it can fully dedicate its binary-search process to hitting your target precisely. Run it again immediately for additional images; there's no limit on repeat uses.

Not directly — this 20KB tool accepts JPG, PNG, WebP, AVIF, GIF, and BMP, but not Apple's HEIC format. Most iPhones convert HEIC to JPG automatically during a browser upload; if yours doesn't, switch to Settings → Camera → Formats → "Most Compatible" first.