Image compression
Reduce the file size of a photo or image by simply dragging the quality slider. The tool re-encodes your image to JPG or WebP at a lower compression quality, so the resulting file takes up less space and uploads faster. Everything runs directly in your browser — the image is never uploaded or stored anywhere.
How image compression works
Photos in JPG and WebP use so-called lossy compression. The image is split into small blocks and fine details that the human eye easily overlooks are simplified or discarded. The amount of this simplification is controlled by quality (0–100): the lower the quality, the more aggressive the compression, the smaller the file and the fewer details. Higher quality keeps more detail but the file is larger.
This tool loads your image onto a canvas in the browser and re-encodes it at the chosen quality and format. The dimensions (width × height) stay the same — only the file size changes, not the pixel count. If you need to change the resolution too, use the resize tool. The input can be any common image (JPG, PNG, WebP…), and the output is a new compressed JPG or WebP file to download.
Note: compression is lossy and irreversible. Re-encoding discards detail, and raising the quality again will not bring it back. Always work from the original, not from a file that has already been compressed once.
How to use image compression
- Drag an image into the field or click to choose a file from your disk.
- Use the slider to set the quality (30–95 %). A lower value means a smaller file.
- Choose the target format: JPG (universal) or WebP (usually smaller at the same quality).
- The tool immediately shows a preview and a comparison: original size → new size and by how many percent the file shrank.
- Click Download and save the compressed image.
Example of how the size of a 3000 × 2000 px photo changes at different quality settings (approximate values, depending on image content):
| Quality | Format | Approx. size |
|---|---|---|
| 95 % | JPG | ~2.4 MB |
| 75 % | JPG | ~900 kB |
| 75 % | WebP | ~600 kB |
| 50 % | JPG | ~450 kB |
What image compression is good for
Compressed images are useful anywhere file size matters: faster page loading and better SEO, e-mail attachments under the limit, uploads to e-shops, listings and social media, or simply saving storage space. The WebP format usually achieves the same visual quality as JPG at a noticeably smaller size and is ideal for modern websites.
Practical tips: for web photos, a quality around 70–80 % is usually a good compromise. For thumbnails and previews you can go even lower. For graphics with sharp edges, text or transparency (logos, screenshots) lossy compression creates artifacts — there PNG via the format converter tool is a better fit.
Privacy: the entire conversion runs locally in your browser using HTML5 canvas. The image never leaves your device, is not uploaded to any server and is not stored. You can therefore safely use the tool even for sensitive or personal photos.
FAQ
Will the image lose quality?
Yes, both JPG and WebP use lossy compression, so some detail is discarded irreversibly. At a reasonable quality (70–85 %) the difference is usually imperceptible to the eye, but the file is significantly smaller.
Will the image dimensions shrink too?
No. Compression only changes the file's data size; the pixel count (width × height) stays the same. If you want to reduce the resolution, use the Resize image tool.
What is the difference between JPG and WebP?
WebP is a more modern format that usually produces a smaller file than JPG at the same visual quality. JPG, on the other hand, is supported everywhere. Choose WebP for the web, JPG for maximum compatibility.
Is my image uploaded to a server?
No. All conversion happens locally in your browser via HTML5 canvas. The image is never sent or stored anywhere, and it even works offline.
Can I compress a PNG?
You can upload a PNG as input, but the output is always JPG or WebP (lossy formats). A PNG with transparency gets a white background when converted to JPG; WebP preserves transparency.
Why does the file sometimes get bigger after compression?
If you upload an already heavily compressed or small JPG and choose a high quality, re-encoding may slightly increase the size. Lower the quality, or work from a less compressed original.
Can I restore the original quality?
No. Lost detail cannot be recovered by raising the quality again. Always keep the original and compress from it.
Is there a size limit for images?
The tool runs in the browser's memory, so very large images (tens of megapixels) may be slower or limited by device memory. Ordinary photos from phones and cameras are handled without problems.
Sources & standards
📅 Last updated: 11 July 2026