How does it hit a specific file size?

It binary-searches the JPEG quality setting, re-encoding the image at successively narrowed quality levels until the result is at or below your target size while keeping quality as high as possible.

What if my target is too small to reach?

If even the lowest quality overshoots, the tool keeps the smallest result it can produce and tells you its size, so you can raise the target or resize the image first.

What format does the compressed image come out as?

JPEG. The tool re-encodes to JPEG because its quality setting can be tuned smoothly to hit a target size, which is ideal for photos. PNG and other lossless formats cannot be dialled to an arbitrary size this way.

Why use binary search instead of trying every quality?

Binary search reaches the right quality in only a handful of re-encodes (roughly log₂ of the range) rather than trying every level, so it is fast even for large images while still landing close to the highest quality that fits.

Is my image uploaded for compression?

No. The compression uses your browser's canvas toBlob, so the photo is processed locally and never leaves your device.

Compress Image to Target Size

This tool compresses an image to fit under a specific file-size limit — for instance the 200 KB cap many forms and uploaders enforce. Choose your target in kilobytes and it shrinks the image to fit while keeping it as sharp as possible. It is ideal for passport-photo uploads, job applications and any site that rejects files over a set size, and it works entirely in your browser.

How it works

The image is drawn onto an HTML canvas, then re-encoded as JPEG via canvas.toBlob, whose quality parameter (0 to 1) trades sharpness for size. To hit your target efficiently, the tool runs a binary search on the quality value: it tries a mid-level quality, checks whether the resulting blob is under your target, and narrows the range up or down accordingly. After a few iterations it settles on the highest quality that still fits. If even the lowest quality overshoots, it keeps the smallest result and reports its size.

Example

For a 1.8 MB photo with a target of 200 KB, the tool might test quality 0.5 (still too big), then 0.25 (under target), then 0.37, converging on, say, quality 0.31 that produces a ~195 KB JPEG. You download that file, comfortably under the limit and as sharp as the size allows.

All compression happens in your browser via the canvas API, so your image is never uploaded.