Compress JPEG Images Online for Free

Processing securely on your device, no data sent to any server

or drop files here

Fine-grained quality control via the MozJPEG encoder, directly in your browser. Nothing uploaded, nothing stored.

How it works

Three steps. Done in seconds.

Drop your JPEG

Drag a JPEG or JPG file onto the zone or click to browse. No file size limit, all processing stays local.

Set your quality level

Lower values produce smaller files. Quality 75-85 is the standard for web and email. The MozJPEG encoder runs locally on your CPU.

Save the result

Compare sizes with the before/after slider, then save your compressed JPEG. No data is sent over the network at any point.

Why it matters

Where JPEG compression makes the biggest difference.

A phone camera JPEG can hit 6-10 MB. For most uses, 300-600 KB is more than enough at identical visible quality.

Websites and landing pages

Hero images account for most page weight. A 6 MB JPEG compressed to 350 KB loads 17x faster, directly improving Core Web Vitals LCP scores and Google rankings.

Email attachments

Gmail caps attachments at 25 MB, Outlook.com at 20 MB, and many corporate servers at 10 MB. Compressing first ensures photos send reliably without bouncing.

Social media uploads

Instagram, Facebook, and X recompress every image on upload. Pre-compressing at your chosen quality gives you control over the final result instead of letting the platform decide.

E-commerce product photos

Product pages with fast-loading images have lower bounce rates and higher conversion. Shopify and WooCommerce both recommend keeping product images under 1 MB.

Platform upload limits

Real estate portals, job boards, school submission systems, and government forms routinely cap image uploads at 1-5 MB. Compressing first prevents rejected uploads.

Messaging and mobile sharing

WhatsApp, Telegram, and iMessage all compress images again on send. Sharing a pre-compressed JPEG uses less mobile data and preserves more detail than letting the app crush it.

How JPEG compression works under the hood.

Unlike most online tools that upload your file to a remote server, this compressor runs entirely in your browser tab. Your JPEG is decoded into raw pixels and re-encoded with MozJPEG, Mozilla's optimised JPEG encoder compiled to WebAssembly, at your chosen quality level. The quality parameter directly controls how aggressively the JPEG DCT coefficients are quantised.

Your file never leaves your device. There is no upload, no server, and no risk of your photos being stored or accessed by anyone else. Closing the tab immediately clears all image data from browser memory.

Common questions

Questions answered.

What JPEG quality setting should I use?

For websites and social media, 70-85 is the sweet spot. Files are typically 60-75% smaller than quality 100 with virtually no visible difference at screen sizes. For print or archival, use 90-95. For thumbnails or previews, 50-65 is acceptable.

Does JPEG compression permanently reduce quality?

Yes. JPEG is a lossy format. Each time you compress and re-save a JPEG, some image data is discarded. Keep the original file and use the compressed version only for its intended purpose (web, email, etc.).

What is the difference between this and converting to WebP?

WebP achieves smaller file sizes than JPEG at equivalent visual quality. If you need a JPEG specifically, for a platform requirement, email compatibility, or printing, use this compressor. If format does not matter, converting to WebP will give you an even smaller file.

Is my JPEG uploaded to a server?

No. All compression runs in your browser using MozJPEG, compiled to WebAssembly. Your file never leaves your device, not even temporarily.

Can I compress multiple JPEG files at once?

Yes, up to 20 files at a time. All processing runs locally in your browser.

Does compressing a JPEG change its pixel dimensions?

Not unless it is very large. Compression reduces file size in bytes only, so a 4000x3000 pixel image remains 4000x3000. Images longer than 4096 pixels on their longest edge are scaled down to that limit first. To set exact dimensions, use the Resize Image tool.

What is the maximum file size this tool handles?

There is no file size limit. The only ceiling is the memory available on your device. Very large files may take a moment longer to process.

Why does my JPEG look the same at quality 80 and quality 95?

JPEG quality differences are often imperceptible at screen sizes. At quality 80 the file can be 60% smaller than quality 95 with no visible difference on a monitor. The difference only becomes noticeable when zoomed past 100% or when printing large format.

Related tools

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