Compress Image

Compress an image or JPG to the exact KB limit a form asks for, without guessing. Pick a target such as 200 KB and Dokurapi lowers the JPEG quality one step at a time until the file sits safely under it, then shows you the quality it ended up using. PNG and WebP work too, and you always get a JPEG back.

Pick the size your form asks for

Start from the number printed on the form. The four most common limits each have their own page with the target already set, so all that is left is choosing the photo.

On this site 1 KB means 1,000 bytes, and the tool stops at 94% of your target to leave a 6% safety margin. If your form uses another number, say 150 KB or 300 KB, type it into the custom KB field; a custom value always overrides the preset. Portal limits differ and change over time, so check the current rule first, for example in our SSCASN upload size guide.

Why it runs on your device

Dokurapi has no upload endpoint. Your browser opens, compresses and saves the photo on your own phone or computer, which gives you three practical benefits:

• Personal photos stay with you. ID photos, card scans and selfies are never sent to Dokurapi or anyone else.
• No upload wait. Once the page has loaded, the photo does not travel over the network, so speed depends on your device rather than your connection.
• Location data is stripped. The image is redrawn through the browser canvas, so EXIF details such as camera model and GPS coordinates do not carry over to the file you share.

For the technical background, read how browser-only file tools work.

What the tool does to your image

The image is decoded by your browser, so any format your browser can open works, including JPG, PNG and WebP. Then:

• If the longest side is larger than 2400 px, the image is scaled down to 2400 px.
• It is encoded as JPEG starting at the starting quality slider value, 84% by default.
• If the file is still too big, quality drops by 10 points per step, for up to 7 steps, and never below 18%. If the file is still too big at the 18% floor, the tool then shrinks the pixel dimensions step by step (never below 640 px on the longest side) and shows the final dimensions in the result.
• It stops at the first result under the safe target, which is your limit times 0.94.

The output is always JPEG. Transparent areas in a PNG become white, which is fine for photos and documents but worth knowing if you are compressing a logo.

Reading the result

After compression you see the original size, the new size, the JPEG quality used and the final pixel dimensions. A quality in the 60s to 80s generally looks close to the original on screen. If the tool had to go down to the 20s or 30s, look closely for blocky edges around text and faces. In that case, cropping away empty background before compressing gives the encoder less to store and lets it keep a higher quality.

If the target cannot be reached even at the minimum quality, the tool says so and still offers the smallest version. Try a lower resolution source or a tighter crop. If you need several photos in one document, convert them with photo to PDF instead.