Free image compressor
This free image compressor makes JPG, PNG and WebP files smaller right in your browser. Pick a quality level, add up to 100 images and download them one by one or as a ZIP. Nothing is uploaded, and there is no sign-up or daily limit.
How to compress images
- Drop, browse or paste your images into the box above: up to 100 at a time, 50 MB each.
- Set the quality. The default of 78 suits most photos.
- Optionally choose WebP as the output format, or set a maximum width to shrink oversized photos at the same time.
- Download each image, or click Download all (ZIP).
- Changed your mind? Adjust the settings and click Apply new settings. The tool starts again from your original files, so images never lose quality from being compressed twice.
Lossy vs. lossless: what the quality slider does
JPG and WebP compression is lossy: the encoder discards detail your eye is unlikely to notice. The quality slider controls how much. Lower numbers give smaller files and, eventually, visible blur and blocky edges around text and sharp lines.
For photos, settings between 70 and 85 are usually hard to tell apart from the original at normal viewing size. Go higher for screenshots, images with text or fine product detail. If a result doesn’t look right, raise the quality and apply the new settings.
PNG is lossless, so the slider doesn’t apply to it. The compressor re-saves PNGs and keeps your original whenever the new file would be larger. To make a photo saved as PNG much smaller, change the output format to WebP or JPG.
How small should web images be?
There is no single right number, but these rules of thumb work for most sites:
| Image | Typical display width | Aim for |
|---|---|---|
| Full-width hero | 1600–1920 px | Under 200 KB |
| Blog or content image | 800–1200 px | Under 100 KB |
| Product image | 800–1000 px square | Under 100 KB |
| Thumbnail | 300–400 px | Under 30 KB |
Pixel size matters as much as quality. A 4000 px camera photo shown 800 px wide still makes every visitor download all 4000 pixels. Use the max width setting here, or the Image Resizer, to fix that first.
The largest image above the fold is often a page’s Largest Contentful Paint element, so a lighter hero image is one of the quickest ways to improve it. Read more about Largest Contentful Paint (LCP).
Compressing images for WordPress
- Compress before you upload. WordPress creates several resized copies of every upload, and each copy is made from your original.
- WebP works out of the box. WordPress has accepted WebP uploads since version 5.8, so you can upload the WebP files from this tool directly.
- Huge originals still cost you. Since WordPress 5.3, uploads larger than 2560 px are scaled down for display, but the full original is still stored on your server.
- Images aren’t always the whole story. If pages are still slow after optimizing images, the cause is usually render-blocking CSS and JavaScript, slow hosting or heavy plugins.
Image compressor FAQ
Is it really free?
Yes. No account, no daily or monthly limits and no watermark. The only limits protect your browser from running out of memory: up to 100 files and 500 MB per batch, and 50 MB per image.
Are my images uploaded?
No. Compression happens in your browser. Your files aren’t sent to our server and we don’t store them. We count tool usage with Google Analytics, but file names and image content are never sent.
Will compression reduce quality?
Lossy compression removes some detail, but at the default setting the difference is usually not visible on a website. If you can see it, raise the quality and apply the new settings.
Which quality setting should I use?
Start at 78. Use 85–90 for images with text or fine detail, and 60–70 for large background images where small artefacts won’t show.
Why did my PNG barely shrink?
PNG is lossless, so re-saving it can’t remove much. Choose WebP as the output format: it keeps transparency and is usually much smaller.
How many images can I compress at once?
Up to 100 per batch. On iPhone and iPad each image can be up to 16 megapixels, because Safari can’t process larger images reliably.
Related tools
- Image Resizer: too big in pixels, not just in file size? Resize to exact dimensions or a web preset.
- Image Converter: turn JPG and PNG files into WebP for smaller pages.
Still a slow WordPress site?
I’m Shahab Ud Din, a Core Web Vitals specialist, and I built this tool. If images aren’t the whole story, my WordPress speed optimization service fixes LCP, INP and CLS end to end. Get in touch for an audit.