Free tool
Image Compressor — Compress Images Online Free
Shrink photos with a quality slider and a before/after comparison.
What this tool does
Need to compress an image online for free? This tool shrinks a photo to a smaller file size right in your browser, with a quality slider that lets you control exactly how much you compress - and nothing is uploaded. Smaller images load faster, attach to emails more easily, and take up less storage.
Want a smaller file without guessing the outcome? Drag the quality slider to find the sweet spot between file size and clarity, and use the before/after size comparison to see exactly how much smaller your image becomes before you commit. You stay fully in control of the trade-off, so you can push for the smallest possible file or hold on to more detail, depending on what the photo is for.
You can save the compressed result as a JPG, WebP, or PNG, so you can pick the format that fits your needs - a smaller lossy file for sharing and faster web pages, a modern WebP for an efficient balance, or a PNG when you want to keep transparency and crisp edges. Matching the format to the job helps you get the smallest file without sacrificing what matters in the image.
Because the compression runs 100% in your browser, your photos never leave your device and nothing is uploaded to a server. That keeps your images private and makes compressing fast, even when you have several files to get through one after another, with no waiting on uploads or downloads from the cloud. It is a simple, reliable way to lighten your photos for the web, for email, or for storage while keeping full control over how they look.
How to use it
How to compress an image
- 01
Upload your image
Select or drag a photo into the tool. It loads in your browser and is never uploaded.
- 02
Adjust the quality slider
Move the slider to set how much to compress. Lower quality means a smaller file; higher quality keeps more detail.
- 03
Choose an output format
Pick JPG, WebP, or PNG for the compressed result.
- 04
Compare before and after
Check the before/after size comparison to see how much smaller the file has become.
- 05
Download the compressed image
Save the smaller file to your device.
For AI photo creators
Compressing keeps your images light and quick to load - an essential step once you have the photo you want. The bigger question is often where that perfect photo comes from.
We are building LaFoto, an AI photo generator that creates original images from your ideas, ready to compress and share with these tools. It is free to start at launch.
Frequently asked questions
- Is this image compressor free?
- Yes. Compressing photos is completely free and runs directly in your browser with no sign-up.
- Are my images uploaded to compress them?
- No. The compressor runs 100% in your browser, so your photos never leave your device and nothing is uploaded.
- How does the quality slider work?
- The slider sets the compression level. Lowering it produces a smaller file with more compression, while raising it keeps more detail at a larger size.
- What formats can I save as?
- You can output your compressed image as a JPG, WebP, or PNG.
- Can I see how much smaller my image gets?
- Yes. A before/after size comparison shows the original and compressed file sizes so you know exactly what you are saving.
- Does this support AVIF?
- No. The available output formats are JPG, WebP, and PNG.
More free tools
Image compressor at a glance
- Runs in
- Your browser — nothing uploaded
- Account
- Not required
- Cost
- Free, no watermark
- Works offline
- After the page loads
- Formats
- JPEG, PNG, WebP
- File limit
- Your device memory, not a quota
What compression really trades
Why a compressed image looks the way it does
Lossy compression works by discarding the information human vision is worst at noticing. It splits the image into blocks, describes each as a sum of frequency patterns, and throws away the high-frequency terms first — which is exactly the fine detail your eye tends to skip.
Push it far enough and the blocks stop hiding. Flat gradients develop banding, hard edges grow a faint halo, and eight-by-eight squares become visible in skies and skin. Those three artefacts are the signature of over-compression and no later processing removes them.
By destination
How hard should you compress?
Speed is the point, so be aggressive
Page weight is a ranking and conversion factor, and images are almost always the largest part of it. Quality 75 in WebP is a sensible default that most visitors will never distinguish from the original.
Resize before you compress. A correctly sized image at moderate quality always beats an oversized one crushed to the same file size.
- Target under 150KB for a full-width hero.
- WebP at quality 75 for photographs.
- Resize to twice the CSS display width, no more.
The limit is a hard number
Mail servers reject attachments over a fixed size, commonly 25MB total but often much lower on corporate systems. Chat apps re-compress anything you send anyway, usually worse than you would.
Compressing to just under the limit is the wrong instinct — sending something well under it means the recipient system does not re-process it a second time.
- Aim comfortably under the limit, not just beneath it.
- Several small attachments beat one large archive.
- Re-compression by the platform is a second generation of loss.
When you should barely compress at all
An archive copy is the one you will re-edit, re-crop and re-export from in five years. Every generation of loss you bake in now is permanent, and no future tool recovers it.
Keep the original file untouched and compress copies. Storage is cheaper than the photograph you cannot re-take.
- Keep one lossless master; export compressed derivatives.
- Never overwrite an original with a compressed version.
- PNG or lossless WebP for anything you will edit again.
When compression goes wrong
What the image compressor handles
The failures people bring, and what actually caused each one.
Blocky squares in the sky
Classic over-compression. Skies are large smooth gradients with almost no detail to hide the block structure, so they show damage before anything else does.
A halo around text or a logo
Ringing, caused by lossy compression on hard edges. Flat graphics belong in PNG or lossless WebP, where this cannot happen.
The file barely got smaller
It was probably already compressed. Re-compressing an image that has been through the process once adds damage without much size benefit.
A screenshot that looks smeared
Screenshots are flat colour and text, which is the worst case for lossy compression. Convert to PNG rather than compressing harder.
Colours shifted slightly
Chroma subsampling — the encoder stores colour at lower resolution than brightness. It is invisible on photographs and obvious on saturated flat graphics.
Related free tools
Tools that pair with compression
Beyond compression
Generate the image, then optimise it
Compression is the last step. These are the first.
- resize an image
- convert an image format
- image compressor
- crop an image
- image colour palette
- cut out a subject
- read photo metadata
- structure a prompt
- anime AI generator
- cartoonize a picture
- pixel art style
- the ranked comparison
- Midjourney alternative
- compared with Leonardo
- LaFoto vs Ideogram
- compared with Canva
- seeds explained
- what is denoise strength
- what is inpainting
- guides and explainers
Start creating today
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