Who asks for 100 KB?
100 KB is a common ceiling for photo uploads on visa, exam and membership portals, and for some government forms that accept a scanned document page. It is enough for a clear head-and-shoulders photo or a legible single-page scan at modest resolution.
Photos
A 600 × 800 px portrait at JPEG quality around 80 is usually 60–100 KB, which is a good target: sharp enough for any on-screen check, small enough for the limit. Crop away background before compressing and the tool can keep a higher quality. If the portal has exact pixel requirements, set them as the maximum width and height, or use the passport and visa photo maker for documents with defined photo rules.
Scanned documents
A full A4 page at 100 KB needs care: around 1,000 px wide in greyscale keeps body text legible. Colour scans of text pages waste most of their bytes on colour that is not there. If the portal accepts PDF, a compressed PDF of the page may look better at the same size.
Why not just lower the quality?
Below about quality 50, JPEG artefacts become obvious: blocky skin, halos around edges, smeared text. Reducing dimensions to what the portal actually displays removes bytes without those artefacts, which is why the search shrinks the image when quality alone would go too low.
Check the result
The note under each result shows the dimensions, quality and size. Look at it at 100% before uploading, especially text and faces.
Step by step
- Add the photo or scan, ideally the original from your camera or scanner rather than a copy sent through a messaging app.
- If the form gives pixel dimensions, type them as the maximum width and height above the button.
- Leave the format on JPG unless the form accepts WebP; JPG is what visa, exam and membership portals almost always want.
- Click Compress to 100 KB. The result shows the final size, dimensions and quality.
- Open the downloaded file and check it at 100% before uploading: faces clear, text legible.
What to expect at 100 KB
As a rough guide, 100 KB is enough for a portrait photo or a small document scan at about 600 × 800 px. The exact numbers depend on the content: plain backgrounds and soft light compress far better than busy, high-contrast scenes. Because the tool measures every attempt, you get the highest quality that genuinely fits rather than a guess that might be over the limit or needlessly blurry.
Troubleshooting
- The form says the file is still too big. Some forms count 1 KB as 1,000 bytes, not 1,024. Lower the target by about 3% and run it again.
- The form says the image is too small. It has a minimum pixel size or minimum file size as well. Set the maximum width and height to its stated dimensions, and use a higher quality.
- The photo looks blocky. Crop away background so the same bytes are spent on the subject, or start from a sharper original.
- The upload is refused as the wrong type. Check the file ends in .jpg; some forms reject .jpeg or WebP. Rename it if needed; the content is the same.
Private by design
The image never leaves your device. It is decoded in your browser, processed in a background worker by open-source codecs compiled to WebAssembly (MozJPEG, libwebp, libavif and OxiPNG, via the jsquash project, plus pica for resizing) and handed back as a download. There is no upload, no account and no server copy to delete. You can confirm it in your browser's developer tools: the Network tab shows the page's own files and the codec files loading, and nothing carrying your image. After the first visit the tools work offline.