Compress Image to 20KB

Twenty kilobytes is one of the tightest limits you will meet online, and it turns up in serious places: exam registrations, scholarship and university portals, recruitment boards and government services that want a small photo and a scan of your signature. A single phone picture can be two hundred times that size.

This page opens with that job already chosen. The target sits at 19 KB, just under 20 whether the website counts a kilobyte as 1,000 or 1,024 bytes, and the output is JPG, which these portals nearly always ask for. The tool keeps the best quality the limit allows, and if lowering quality is not enough it reduces the pixel size step by step until the file fits.

At 20 KB something has to give, so the page is honest about it: each result shows the quality used and any new pixel size, and you can compare it with the original before you download. Your pictures stay on your device the whole time; nothing is uploaded.

1. Tap “Choose files”, drop the photo and the signature scan on the box, or paste one. Up to 20 at once.
2. The line above the tool confirms the job: under 20 KB, saved as JPG. If your form gives a lower limit, type it into “At most”.
3. Press “Compress to 19 KB” (the button names your target). Each row shows its final size, quality and pixel size.
4. Tap a row to compare it with the original, then press “Download”. Several files arrive as one ZIP.

• Ready for 20 KB limits: target 19 KB (19,456 bytes), saved as JPG.
• Searches for the highest quality that fits, never below 30%, then shrinks the pixel size in 80% steps if needed.
• Each row reports the new size, the quality used and any change in pixel size.
• Reads iPhone HEIC, PNG, WebP, AVIF, TIFF, GIF, BMP, SVG and ICO; sideways phone photos are turned upright.
• Up to 20 images per batch, downloaded singly or as one ZIP.
• Every setting can still be changed, from 20 KB, 50 KB and 100 KB buttons to any limit you type.

• For a signature, crop tightly around the ink first (Crop Image). Empty paper wastes most of the 20 KB.
• Sign with a thick black pen on plain white paper and photograph it in daylight: high contrast survives compression best.
• If the portal also gives pixel sizes (for example 140 × 60), resize to those first, then compress here.
• Many portals want a photo between 10 and 20 KB. If yours sets a minimum too, raise “At most” rather than going far below it.
• Transparent areas in a PNG signature turn white in the JPG, which is what forms expect.