Image Compressor
Compress JPEG, PNG and WebP images by re-encoding at a lower quality locally in your browser — files never leave your device, and before/after sizes are shown before you download.
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Compress your image locally
No upload or network request — files never leave your device. Animated images become a single frame and metadata (EXIF) is not preserved.
Output keeps the source format, except PNG sources are re-encoded as JPEG to achieve real savings (transparency becomes white).
What this tool does
Compress JPEG, PNG and WebP images by re-encoding at a lower quality locally in your browser — files never leave your device, and before/after sizes are shown before you download. Processing happens in the ImageTools panel below. Lower quality means smaller files and more artefacts; PNG sources are re-encoded as JPEG or WebP to achieve real savings (PNG itself is lossless). Inputs are capped at 30 MB / 40 megapixels.
How to use the Image Compressor
- Enter or select compression quality (%).
- Read the calculated result; change any measurement to compare alternatives.
Formula
Decode the local image, draw it to a Canvas at native size, and re-encode as JPEG or WebP with canvas.toBlob(type, quality/100); the size saving is the byte difference between source and output.
- quality
- Compression quality (%)
Processing happens in the ImageTools panel below. Lower quality means smaller files and more artefacts; PNG sources are re-encoded as JPEG or WebP to achieve real savings (PNG itself is lossless). Inputs are capped at 30 MB / 40 megapixels.
Worked example
For image compressor, the following measurements illustrate the exact method: Compression quality (%): 70.
Inputs
- Compression quality (%)70
Result
- CompressionSelect a local image in the panel below to compress it and download the smaller copy.
Results explained
- Compression
- Compression from the formula above. Processing happens in the ImageTools panel below. Lower quality means smaller files and more artefacts; PNG sources are re-encoded as JPEG or WebP to achieve real savings (PNG itself is lossless). Inputs are capped at 30 MB / 40 megapixels.
Frequently asked questions
70-85% is the usual sweet spot for web photos: large savings with artefacts most viewers will not notice. Go lower (40-60%) for thumbnails, and preview the result before publishing.
PNG is lossless, so re-encoding it as PNG saves little. The compressor offers JPEG/WebP output for photos; keep PNG only when you need lossless quality or transparency.
No. Compression here keeps the pixel dimensions and only changes encoding quality. Use the Image Resizer when you also need smaller dimensions.
No. Files are decoded and re-encoded with the browser Canvas API on your device. There is no upload, no server and no network request — you can verify by processing an image while offline.
Canvas re-encoding does not copy EXIF, GPS or camera metadata into the output — a privacy benefit, but copy any metadata you need before converting.