Image compressor help

The Image Compressor re-encodes one selected image locally in your browser, keeps the original dimensions, previews the result, and shows output file size before download.

Supported Files

Use common browser-readable still images such as PNG, JPG, JPEG, WebP, and BMP. Animated images, very large files, unusual color profiles, or files your browser cannot decode may fail or export only a still frame.

Local Processing And Privacy

PixTools does not require an account and does not upload your selected image to a PixTools server for compression. The preview and download are created by your browser's image and Canvas APIs.

Compression Versus Quality

The slider is labeled Compression because higher values request more of the available browser-side size reduction for the selected file. The default is 20%. At 0%, JPEG and WebP originals are preserved; PNG and BMP still convert to JPEG. At 100%, the browser uses its lowest quality setting. Intermediate values use a bounded quality search for the requested portion of the available reduction.

Maximum File Size In KB

Choose Maximum file size and enter a whole number from 1 to 25000. One KB means 1,000 bytes: 100 KB allows 100,000 bytes, and 200 KB allows 200,000 bytes. The tool compares actual output bytes against the limit and enables download only for a current result that fits. It keeps the original dimensions.

The bounded search does not guarantee the best possible quality or an exact file size. If the attempt cannot meet your limit, download stays disabled and the smallest produced size is shown. Increase the limit or use Image Resizer first. It never resizes automatically.

JPEG and WebP originals already within the limit pass through byte for byte. PNG and BMP still convert to JPEG. Replacing an image remembers the mode and KB limit; the percentage slider resets to 20%.

PNG And BMP Limits

Browser PNG export is lossless, so a quality-style slider does not reduce PNG output the same way it does for JPEG or WebP. This compressor exports PNG and BMP originals as JPEG so the compression setting can affect file size. Transparent pixels are flattened onto white.

Downloads

The download button uses only a result that matches the current file and valid settings. Invalid or pending limits cannot download a previous result. Filenames add a compressed suffix and use the output extension, such as JPG or WebP.

Troubleshooting

If preview or download fails, try a smaller image, reduce compression, refresh the page, or use a current version of Chrome, Edge, Firefox, or Safari. If the result is larger than expected, increase compression or resize the image first.

Related Tools

Use Image Resizer when dimensions also need to change, Image Converter when the file type is wrong, or Image Upscaler when a small source needs a larger copy.

FAQ

Does compression resize my image?

No. The compressor keeps the original pixel dimensions. Use Image Resizer when width or height changes.

How does the compression slider work?

The slider is scaled to the selected file. 0% keeps JPEG/WebP bytes (PNG/BMP convert to JPEG), while 100% uses the lowest browser quality setting. Values between them aim for that part of the available reduction.

Can I compress to a maximum size in KB?

Choose Maximum file size and enter a whole number from 1 to 25000 KB. 1 KB is 1,000 bytes. Download is available only when the current result is at or below the limit. If the attempt cannot meet it, resize first or increase the limit. Dimensions never change automatically.

Why did my PNG become JPEG?

PNG and BMP originals export as JPEG in this tool so the compression slider can affect file size. Transparent pixels are flattened onto white.