Image Compressor & Optimizer
Reduce photo file sizes by re-encoding them as JPEG at a quality level you choose. The image is decoded to a canvas in your browser and written back out at the target quality, so you can watch the size drop and stop at the point where the picture still looks right.
How it works
- 1
Select a photo from your device — the file is read into browser memory, not uploaded.
- 2
Set the quality slider. Around 75 percent is the usual sweet spot for photographs.
- 3
Compress, then compare the new file size against the original.
- 4
Download the compressed JPEG, or raise the quality and try again if the result looks soft.
What people use it for
- Getting a photo under an email or upload size limit.
- Shrinking oversized images that are slowing down a web page.
- Preparing pictures for a listing, form submission or support ticket.
- Reducing a batch of screenshots before attaching them to a document.
Supported formats & options
| Input | Any image format your browser can decode, including JPG, PNG, WebP and GIF (first frame) |
|---|---|
| Output | JPEG only |
| Quality range | Adjustable JPEG quality, with roughly 75 percent as a practical default |
Key advantages & benefits
You control the trade-off
The quality slider is the actual JPEG quality parameter, so you decide where the balance between size and detail sits rather than accepting a fixed preset.
Real size feedback
Original and compressed sizes are shown together, which is the number that matters when you are fixing a slow page or an attachment limit.
No upload queue
Compression runs on your own CPU, so there is no waiting for a server slot and no file-count limit to pay for.
Private by construction
The photo never leaves the tab, which matters for client work, screenshots of internal tools and personal pictures.
Limits & things to know
- Output is always JPEG. That is the right choice for photographs, but it is the wrong one for logos, screenshots of text and line art, which stay sharper as PNG — use the image converter for those.
- JPEG has no alpha channel, so a transparent PNG comes back with a solid background. Convert to WebP instead if you need transparency and smaller files.
- Re-compressing an image that is already a JPEG loses a little more detail each time. Always start from the highest-quality original you have.
- Very large images are limited by browser canvas memory; a phone will run out sooner than a desktop.
Troubleshooting
The compressed file is larger than the original
The source was probably already compressed harder than your chosen quality, or it was a PNG of flat colours that JPEG encodes badly. Lower the quality, or keep the original.
Text or edges look smudged
JPEG blurs sharp edges by design. For screenshots and graphics, convert to PNG or WebP with the image converter rather than compressing as JPEG.
The transparent background turned black or white
JPEG cannot store transparency. Use WebP output in the image converter to keep the alpha channel.
Privacy & data handling
Your photo is read with the File API and re-encoded on a canvas inside your browser. It is never uploaded, so there is no copy on our server to delete and no retention period to trust.
Image Compressor — Compress JPG & PNG Online Free
Reduce image file size without an obvious drop in quality, directly in your browser. A free image compressor for getting photos under an upload limit, cutting page weight for Core Web Vitals, and shrinking email attachments — with a live before-and-after preview so you control the trade-off yourself.
- Compress JPG, PNG and WebP — typical photographs lose most of their file size with no visible difference at normal viewing distance.
- Hit a specific size limit — tune quality until the file fits the ceiling in front of you — a 100KB form upload, a 2MB portal cap or an email attachment limit.
- Faster pages and better Core Web Vitals — images are usually the heaviest thing on a page, so compressing them is the single biggest Largest Contentful Paint win available.
- Visual quality control — compare original and compressed side by side before downloading, instead of trusting a fixed preset.
- No upload, no watermark — compression runs on a canvas in your browser, so private photos and client work never reach a server.
Free with no daily limit. Change the pixel dimensions too with the Image Resizer, or switch format entirely with the Image Converter.
Frequently asked questions
Are my photos uploaded to a server?
No! Image compression happens entirely in your browser using Canvas encoding APIs.
What quality setting should I use?
Around 75 percent is the usual balance for photographs — a large size reduction with little visible difference. Compare against the original at full size before going lower, since the point where artefacts appear depends on the picture.
Why did my PNG get worse instead of smaller?
Output is JPEG, which is built for photographs. Screenshots, logos and line art have hard edges that JPEG blurs, and flat colour that it encodes inefficiently. Use the image converter to output PNG or WebP for those.
Can I compress the same image twice?
You can, but each pass discards more detail permanently. Always start again from the highest-quality original rather than re-compressing an export.
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