Re-encode a local image and compare its original and downloaded file sizes.
n Inputs are processed locally by this tool. Other site plugins, hosting logs, ads and embeds have their own data handling. Text limit: 1 MiB UTF-8.
How to use Image Compressor
- Choose an authorized local image.
- Select a format and, for JPEG/WebP, quality.
- Compare the preview and sizes before downloading.
Example
Try a photograph in WebP at quality 0.8 and compare the output size and visible detail. Use PNG when lossless transparency matters.
Method and formula
The image is decoded locally and drawn to a canvas at its original pixel size, then encoded in your chosen format. JPEG output uses a white background for transparent pixels. PNG ignores the lossy quality setting. The result shows original bytes, output bytes and percentage saved.
Limits and supported input
JPEG, PNG and WebP only, up to 15 MiB and 24 million source/output pixels, with each output side at most 8,000 pixels. GIF, SVG, APNG and animated WebP are rejected. Browser format support varies. Canvas re-encoding can remove metadata and change colour handling; keep the original. Output can be larger than the input; no savings are guaranteed.
Privacy
This tool processes the input in your current browser tab. It does not upload your input or call a paid or remote API. Copying places text on your system clipboard; downloading saves a file on your device. Site hosting logs, analytics, ads, third-party embeds and other installed plugins are separate and can have their own data handling. JavaScript is required for the tool, while this explanation remains available without it.
Frequently asked questions
Are images uploaded?
This tool reads the file in your browser and makes no upload request.
Why is PNG larger?
Re-encoding can create a larger file; the tool reports this honestly.