Compress JPEG Images Online Free
Reduce JPEG photos to a size you specify, straight from your browser. Set a target in kilobytes, upload, and download a smaller file in seconds.
You can also compress any image to a target size, or compress PNG images, or compress WebP images.
Why compress JPEG here
- Target an exact sizeSet the figure your form or mailbox demands instead of guessing at a quality slider.
- Large savings on phone photosModern phone images carry far more detail than any screen displays.
- Batch several photosCompress a whole set towards the same target in one pass.
- Free, no watermarkNo account and nothing added to the image.
How to Compress a JPEG Image (Step-by-Step)
- 1
Upload your JPEG image
Click the upload button or drag in your JPEG file.
- 2
Set a target size
Enter the size in KB you need the finished file to fit within.
- 3
Click Compress
The image is reduced towards your target in a few seconds.
- 4
Download the result
Download immediately — no account, no email, no watermark.
When to compress a JPEG
JPEG is already the efficient option, so compressing further is usually about meeting a specific limit rather than saving space for its own sake:
- Attaching photos to an email: Several full-size images will exceed a typical mailbox limit; compressed ones will not.
- Uploading to a form with a KB cap: Application portals and job sites almost always impose one.
- Publishing to a website: Page weight directly affects loading speed and search ranking.
- Freeing up storage: A folder of holiday photos reduces enormously with little visible change.
How JPEG compression actually works
JPEG discards information the human eye is poor at noticing. It is far more sensitive to brightness than to fine colour variation, so the format keeps luminance detail and throws away colour detail, then breaks the image into small blocks and stores a simplified approximation of each one.
At high quality settings that approximation is close enough that no one can tell. As the quality drops, the blocks become progressively cruder, which is why heavily compressed JPEGs develop that characteristic squared-off mottling — you are seeing the blocks themselves.
Our compressor starts at maximum quality and steps down until your target size is met, so it uses the highest quality that satisfies the limit you set rather than jumping straight to an aggressive setting.
Why compressing an already-small JPEG disappoints
If a file has already been compressed hard, most of the discardable information is gone. Asking for a further large reduction means the encoder has to start removing detail that genuinely matters, and the result degrades quickly and visibly.
This is why the same target size gives such different results depending on the source. A 6MB photo straight from a camera reduced to 200KB usually looks excellent. A 300KB image that has already been through two other tools, reduced to 200KB, can look noticeably worse despite the far smaller change.
Where you have the choice, always compress from the largest, least-processed original you have rather than from a copy someone already shrank.
Choosing a sensible target
Work backwards from the actual requirement. If a form allows 100KB, target 100KB — not 50KB for safety. Every kilobyte you give up below the limit is detail discarded for no reason.
If you have no external limit and simply want smaller files, a few hundred kilobytes is generally ample for a photograph viewed on a screen. Below roughly 50KB, compression artefacts start becoming visible in detailed images.
Resizing helps more than compression when an image is far larger than its display size. A 4000-pixel-wide photo shown at 800 pixels gains nothing from the extra width, and reducing the dimensions first produces a far better result at any target.
Privacy and Security
Every image you upload is transmitted over an encrypted HTTPS connection. Once compression finishes and you have downloaded the result, both the original and the compressed copy are permanently deleted from our servers. We never store, view or share your files.
Frequently Asked Questions
Does compressing a JPEG twice make it worse?
Yes, slightly, each time. JPEG is lossy, so recompression works from the already-approximated version rather than the original. A single pass is normally invisible; repeated passes accumulate visibly.
What target size should I choose?
The largest one your form or mailbox allows. Compression cannot be undone, so going smaller than required only discards detail for nothing.
Why did my already-small JPEG come out looking poor?
Because most of the discardable detail had already been removed. Compressing from the largest original you have gives a far better result than compressing an already-shrunk copy.
Can I compress several photos at once?
Yes. Upload a batch and each is compressed towards the same target size.
Are my photos stored?
No. Files are transferred over an encrypted connection and deleted automatically once processing finishes.