For a faster website
Compress images online for free
Make JPG, PNG, WebP and AVIF files smaller right in your browser. No sign-up, and your images never leave your device.
or drop them here · paste with Ctrl+V
JPGPNGWebPAVIFUp to 20 images · 30 MB each
Drop images to compress
Compressed on your device. Nothing is uploaded.
Lighter images are one part of a fast page. Test your page speed →Want the whole site done for you? Speed fix from
1.4 MB · JPG
157 KB · WebP−89%Same photo, 89% lighter
A typical photo for a website: 4000 pixels wide and 1.4 MB. With the default Balanced quality, WebP and a 1920 px max width it stays sharp even on a large screen and weighs 157 KB.
- Original
- JPG · 4000 × 2500 · 1.4 MB
- WebP
- 1920 × 1200 · 157 KB · −89%
- AVIF
- 1920 × 1200 · 169 KB · −88%
- Settings
- Balanced · 1920 px
How to compress images
Add your images
Drop JPG, PNG, WebP or AVIF files on the box above, up to 20 at a time.
Compress on your device
Your browser shrinks them with open-source encoders. No uploads.
Download the results
Save the files one by one, or all of them at once as a ZIP.
More about compressing images
JPG, PNG, WebP or AVIF: what FlashMax does
| Format | What FlashMax does | Best for |
|---|---|---|
| JPG / JPEG | Re-encodes it with mozjpeg at the quality you choose. The new file carries no location or camera data. | Photos |
| PNG | Optimizes it with OxiPNG without changing a single pixel. For a much smaller file, convert it to WebP. | Logos, screenshots, images with transparency |
| WebP | Re-encodes it with libwebp at the quality you choose. | Most website images: every current browser shows WebP |
| AVIF | Re-encodes it with libavif at the quality you choose. Slower to make, often the smallest file. | Photos where every kilobyte counts: every current browser shows AVIF |
In our test on 51 images from one live website (November 2026), JPEG photos got 52% smaller on Balanced, and PNG images converted to WebP got 86% smaller. Files that are already well compressed can’t shrink much: when a new file isn’t at least 10% smaller, FlashMax keeps the original.
Images for a fast website
- Upload at about twice the size they’re shown. A 4000-pixel photo shown 800 pixels wide carries most of its weight for nothing. Pick a Max width before you compress.
- Compress before you upload. Many platforms, WordPress among them, make several smaller copies of every image you upload, so a lighter original makes every copy lighter.
- Use WebP where you can. Every current browser shows WebP. WordPress accepts it since version 5.8; on other platforms, check their list of supported formats.
- Check the page afterwards. The free speed test shows what changed on the page.
Your images stay on your device
FlashMax compresses images inside your browser with WebAssembly. Your files are never uploaded to our servers, so there is nothing for us to store or delete. The JPEG, WebP and AVIF copies don’t carry the location or camera data of the original. Close the tab and the images are gone.
Questions
Is the image compressor free?
Yes. No sign-up and no daily limit: up to 20 images at a time, 30 MB each.
Are my images uploaded anywhere?
No. Compression runs in your browser, on your device. The images are never sent to FlashMax or anyone else.
Will my images lose quality?
JPEG and WebP compression removes detail the eye rarely notices, and Balanced suits most website images. For photos with fine detail choose Higher quality, and check any image with Compare before you use it. PNG optimization keeps every pixel.
Why didn’t my image get smaller?
It was already well compressed. When a new file isn’t at least 10% smaller, FlashMax keeps your original.
Should I convert my images to WebP?
For PNG images, usually yes: in our test they got 86% smaller as WebP. For JPEG photos the gain is smaller, so keep JPEG if your site or a service needs it. Every current browser shows WebP. AVIF files are often smaller still, but take longer to make.
Will compressing images make my site faster?
Lighter images download faster, which matters most on phones. How much it helps depends on the page, so test it with the free FlashMax speed test before and after.
Which files can I compress?
JPG, PNG, WebP and AVIF, up to 30 MB and 50 megapixels each. iPhone photos usually arrive as JPEG; HEIC and GIF aren’t supported yet.
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