Reduce image size in KB
Set a file-size limit and the compressor searches for the highest quality that fits, the easy way to meet upload limits on application forms, portals and marketplaces.
Common size limits
- Compress image to 20 KB: signature and thumbnail uploads on exam and job portals
- Compress image to 50 KB: government and exam application photos (many forms ask for 20–50 kb)
- Compress image to 100 KB: upload fields that cap files at 100 kb
- Compress image to 200 KB: job-application and visa portals with a 200 kb limit
- Compress image to 500 KB: online forms and lms uploads with a 500 kb cap
- Compress image to 1 MB: email attachments and support tickets with a 1 mb cap
How the size search works
File size doesn’t move in a straight line with quality, and every photo responds differently, so a fixed setting can’t promise a size. Instead the tool encodes your image at quality 50, checks the bytes, then halves the range, the same way you’d guess a number between 1 and 100. It needs roughly six or seven encodes. Open “How the size was found” under any result to see every attempt.
Questions
How do I reduce an image to a specific size in KB?
Type the limit into “Target size”, add your image, and the tool tries qualities in a binary search until it finds the highest one that fits. If even the lowest sensible quality is too big, it reduces the pixel dimensions and tries again.
Is 1 KB 1,000 or 1,024 bytes?
This tool counts 1 KB as 1,024 bytes, the way Windows and most upload forms do. If a form means 1,000 bytes, set your target about 3% lower to be safe.
Which format fits the most quality into a KB limit?
AVIF, then WebP, then JPEG, for photos. But most forms with a KB limit only accept JPG, so the size pages default to JPG.