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Compress Image to 100 KB
Compress Image to 100 KB Online — Free & Instant
Compress an image to a 100 KB target for email, forms, and uploads, at the best quality that fits.
About Compress Image to 100 KB
Many websites, email providers, and online forms have a 100 KB file size limit for image uploads. Government portals, job application forms, university admissions, and ID photo submissions commonly require images under 100 KB. This tool compresses your image to fit under 100 KB by iteratively adjusting quality using a binary search algorithm until the target is reached, giving you the best possible visual quality within the size constraint. Everything runs in your browser — your images are never uploaded to any server, which is especially important when compressing sensitive documents like ID photos or personal documents. The tool supports JPG, PNG, WebP, AVIF, and BMP input formats. You can preview the compressed result before downloading to make sure it meets your quality standards. The tool lowers encoder quality first; if quality alone cannot get a very large photo under 100 KB, it also scales the image down in bounded steps, and the result tells you the new dimensions whenever that happens. Batch processing is available for compressing multiple images at once.
Questions
Why do I need to compress to 100 KB?
Many websites, email providers, and online forms have a 100 KB file size limit for image uploads. Passport applications, visa forms, and government websites often have this restriction.
Will my image look bad at 100 KB?
It depends on the image dimensions. A small image (under 1000px) can look great at 100 KB. For larger images, you may notice some quality loss. The tool finds the best possible quality that fits within the limit.
Which input formats can I compress?
JPG, PNG, WebP, AVIF, and BMP are all accepted. Opaque images come out as JPG because it hits target sizes most reliably; images with transparency are saved as WebP automatically so the transparency survives.
Will the output be exactly 100 KB?
No — the tool aims at or just under the limit, never over it when the target is reachable. The quality search stops refining once it lands within 5% of the ceiling, so a large photo typically comes out between 95 and 100 KB; an image already under 100 KB at full quality just stays smaller.
What if my photo can't reach 100 KB at full size?
The tool lowers encoder quality first. When quality alone can't get there, it scales the image down in bounded steps — each between 50% and 90% of the current size, never below 64 px on the longest side — and the result reports the new dimensions. If even that can't reach 100 KB, you get the smallest file it managed, and never one larger than your original.
Is my file uploaded to a server?
No. Transmute processes everything locally in your browser using JavaScript and WebAssembly. Your files never leave your device — there is no server, no upload, no cloud processing.