Image Compressor
How to Use
📖 Tool Introduction
Image Compressor is a free, instant online tool dedicated to shrinking pictures so they fit neatly inside web pages, social posts and app bundles where file size really matters. After you upload an image, the dashboard shows two horizontal bars side by side: the original file size and the compressed size, with a live percentage telling you exactly how much space you saved. The whole tuning process is one slider — drag it left for a smaller file with slightly more visible loss, or right for an output closer to the original at a gentler size reduction. Three output formats are available with a single click: JPEG offers the broadest compatibility, WebP usually delivers the smallest file at the same quality, and PNG stays lossless, which is ideal when transparency or sharp text lines matter. Every compression is performed locally by the browser's built-in Canvas encoder, so your pictures are never uploaded anywhere, and photos up to 20MB are processed smoothly. The interface follows the website theme automatically, is available in Simplified Chinese, Traditional Chinese and English, and works just as well on a phone browser as on a desktop. There is no queue, no waiting screen and no account — open the tool, drop in an image, move the slider until the saved percentage feels right, and download the result. The tool is especially useful for developers and bloggers who need to keep web pages fast: every kilobyte saved on a hero image or a screenshot means less waiting for visitors on mobile networks. Because the conversion happens inside your own browser, there is no upload queue, no file-size cap imposed by a server, and no chance that a private product shot ends up on someone else's disk. The comparison bars update instantly while you drag, so you can stop tuning the moment the numbers look right, and the download uses the exact bytes the encoder produced, with no hidden post-processing step on top.
✨ Key Features
- Live compression: drag the slider and the image re-encodes instantly, no repeated clicks
- Size bars: two tracks show the original and compressed size side by side
- Savings readout: the tool computes the size change and warns when a format grows
- Three formats: universal JPEG, smaller WebP, lossless PNG, switchable in one click
- Automatic white fill: transparent areas become white on JPEG export instead of black
- Fully local: the Canvas encoder runs in your browser, zero uploads and complete privacy
📝 How to Use
- Click the upload area to choose an image, or drag and drop it into the dashed box
- Drag the quality slider and watch the size comparison bars update in real time
- Pick your target output format: JPEG, WebP or PNG
- Stop tuning once the size reduction percentage meets your target
- Click Download result to save the compressed image file
⚠️ Notes
- Lossless PNG: PNG export ignores the quality slider, so it has no visible effect
- Transparency: transparent areas are filled white when exporting to JPEG
- Size grows: a growth warning means the image is near its minimum size — try WebP instead
- Huge images: pictures over 20MB should be cropped or resized first
- Original stays safe: compression creates a new file and leaves the local original untouched