Compress Image to 100KB Online

For most major national exams, yes — JEE Main and UPSC both cite 100KB as the upper limit for signature uploads. A handful of portals (like NEET, capped at 30KB for signatures in some cycles) are stricter, so always check your specific exam's current notification.

Yes, most NTA portals do a hard client-side size check and simply refuse files over 100KB, so 104KB would fail. Compress it to 95–100KB with a small safety margin rather than sitting exactly on the boundary.

Different recruiting bodies set their own technical specifications independently — there's no single national standard. India Post's GDS notification specifies a 320×400px photo which naturally needs a slightly larger file size budget than SSC's smaller 275×354px requirement.

100KB is a safe, detail-preserving choice for most college and university admission portals, which rarely publish government-exam-style strict limits but commonly reject anything over 100KB–200KB to keep their systems fast.

Our tool treats 1KB as 1,024 bytes (the binary definition computers actually use), so choosing 100KB targets a file of at most 102,400 bytes. A small number of strict portals count 1KB as exactly 1,000 bytes instead; in that rare case, aim slightly under 100KB to be safe.

At 100KB, expect quality that is very close to the original, with compression artefacts hard to spot at normal viewing size. Our tool always reduces quality gradually first and only shrinks pixel dimensions if quality reduction alone can't reach 100KB, which keeps the result looking as sharp as possible for this target.

For a 100KB target, our tool rarely needs dimension changes for a typical passport-style 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 100KB. For output, choose Auto (the tool picks the best format for a 100KB target) or force JPG, PNG, WebP, or AVIF specifically using the Output Format dropdown.

No. Compressing to 100KB happens entirely inside your browser using the HTML5 Canvas API — nothing is ever sent to a server. That matters especially for a signature or ID document scan, which you may not want leaving your device at all.

Not currently — this 100KB 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 100KB 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.