How to compress image to 100KB
Many application portals reject photos over 100 KB. Drop your image and this tool returns the sharpest JPG under 100 KB — measured to the byte — without uploading it anywhere.
- Drop, paste or choose your image (JPG, PNG, WebP, GIF, BMP or AVIF). A sample photo is loaded so you can try it first.
- The target is preset to 100 KB. Change it, or pick another preset, if your form asks for something different.
- Optionally choose an output format and a maximum width or height.
- Check the side-by-side preview and the exact byte count, then click Download.
How the compressor hits an exact size
The tool decodes your image in the browser, then re-encodes it with the browser's own JPEG, WebP or PNG encoder. For JPEG and WebP it runs a binary search on the quality setting — usually 6 to 10 test encodes — and keeps the highest quality whose file is at or under your target. If even a low quality (40%) is still too large, it reduces the pixel dimensions by the amount the byte count suggests, then searches quality again, so you get the largest picture that fits rather than a blocky one. PNG is lossless, so for PNG only the dimensions change. If your file is already under the target and you keep the same format, the original is returned untouched.
Everything happens on your device with the Canvas API; nothing is uploaded, and the re-encoded file does not carry the original EXIF metadata (camera, GPS).
Frequently asked questions
How do I reduce a photo to under 100 KB?
Drop the photo here with the target set to 100 KB. The tool lowers JPEG quality step by step (a binary search) and keeps the best result under 100 KB. A typical 12-megapixel phone photo fits at full resolution with a medium quality setting, or with a modest resize if it is very detailed.
Is 100 KB measured as 100,000 or 102,400 bytes?
Sites count it differently. The tool treats 1 KB as 1,024 bytes, so a 100 KB result passes either way, and it shows the exact byte count. If a form still complains, set the target to 95 KB.
My form also needs specific pixel dimensions. Can I set them?
Yes. Enter a maximum width and height under Dimensions. For a fixed square photo, choose “Crop to square” and enter the same width and height.
Which format should I pick for a 100 KB limit?
Use JPEG if the form says JPG/JPEG — it is accepted almost everywhere. Use WebP only if the site lists it; it gives better quality at the same size.
Are my images uploaded to a server?
No. Compression runs entirely in your browser using the Canvas API. The image never leaves your device, which also makes it safe for ID photos and signatures.
Is it free?
Yes. Compressing one image at a time is free with no signup and no watermark. Gridloom Pro adds batch compression of many images with a single ZIP download.