Free Online Image Compressor
Shrink your photos so they load faster and take up less space, without any of them touching a server. Nudge the quality, watch the before-and-after size update, and download files one at a time or bundled in a ZIP. It's made for websites, email attachments and squeezing under storage limits.
- 100% free
- Private & safe
- Runs in your browser
Your files are processed securely in your browser and are not uploaded to our servers.
Why use Compress Image?
Compress Image lets you edit and optimise images in seconds, right in your browser — no bulky software to install and nothing uploaded to a server.
- 100% private: files are processed in your browser and never uploaded.
- Completely free, with no account, no watermarks and no usage limits.
- Handles JPEG (.jpg, .jpeg); PNG (.png); WebP (.webp).
- Drag your images onto the dropzone or pick them with the file button. You can add several at once.
- Works on any device — desktop, tablet and phone — and is fully keyboard accessible.
What it can do — and its limits
- Compresses JPG, PNG and WebP by re-encoding at a quality you choose.
- Batch-compress several images in one go and download them together.
- Shows a before/after preview and the exact file-size saving.
- Processes on your device; very large images (roughly 30–50 megapixels) depend on your device's available memory.
How to use Compress Image
- Drag your images onto the dropzone or pick them with the file button. You can add several at once.
- Choose a quality level. Lower quality means a smaller file; the preview shows the trade-off before you commit.
- Optionally cap the maximum width or height to further reduce size for web use.
- Click Compress. Everything runs in your browser using the browser-image-compression library — no upload happens.
- Download each result, or grab them all in a single ZIP.
Examples
- A 4.2 MB phone photo compressed to around 480 KB for a blog post.
- Batch-compressing 20 product images before uploading them to a store.
Worked example
Input
A 4.2 MB, 4000×3000 JPEG photo saved at quality 100.
Output
≈ 780 KB JPEG at quality 72 — about 81% smaller with no visible difference at screen size.
Savings vary by image: detailed photos compress far more than flat graphics or screenshots.
Supported formats & limits
- JPEG (.jpg, .jpeg)
- PNG (.png)
- WebP (.webp)
Which format to compress to
| Your content | Best format | Why |
|---|---|---|
| Photographs | JPG or WebP | Lossy compression shrinks photos dramatically with little visible loss |
| Logos, icons, flat colour | PNG or lossless WebP | Keeps crisp edges and transparency |
| Web performance | WebP | Typically 25–35% smaller than JPG/PNG at similar quality |
Limitations
- JPEG and WebP compression is lossy — very low quality can introduce visible artifacts.
- Extremely large images may be limited by your device's available memory.
- PNG size reduction is more modest than JPEG because PNG is already lossless.
Common problems & fixes
A PNG barely gets smaller.
PNG is lossless, so photos hardly shrink. Convert the photo to JPG or WebP (with the Image Converter) for large savings.
Colours look washed out or show banding.
Raise the quality slider. Very low quality adds artifacts, especially across gradients and skies.
Transparency turned into a solid colour.
JPG has no transparency. Keep the image as PNG/WebP, or choose a flatten background colour when converting.
Sources & references
Last verified August 2026.
Frequently asked questions
Are my images uploaded anywhere?
No. Compression happens entirely in your browser and your files never leave your device.
Is the compression lossless?
For JPEG and WebP it is lossy, meaning some detail is discarded to save space. PNG stays lossless but shrinks less.
Can I compress many images at once?
Yes. Add multiple files, process them together and download them all as a ZIP.