Compress JPEG images in bulk
Shrink JPG photos with the MozJPEG encoder while keeping them sharp. Drop a single photo or an entire folder – nothing is uploaded.
- No upload
- Free, no sign-up
- Whole folders
- Works offline
Drop images or a folder here
JPG, PNG, WebP, AVIF or BMP · no file limit
Processed on your device. Nothing is uploaded.
How to compress JPEG images
- 1
Add your photos
Drop JPG files or a whole folder onto the tool, or use “Select images” / “Select folder”. Subfolders are included.
- 2
Compression starts automatically
The default 80% quality is the sweet spot for the web. Change it in the settings and click Apply to re-run.
- 3
Compare before and after
Open any result to drag the comparison slider and zoom in on fine detail.
- 4
Download
Save a single photo, a ZIP that keeps your folder structure, or (in Chrome and Edge) write straight back to your folder.
How much smaller will my JPEGs get?
Photos straight from a phone or camera are usually saved at very high quality, so re-encoding them with MozJPEG at around 80% quality typically removes 40–75% of the file size with no difference you can see at normal viewing size.
Images that were already compressed for the web shrink less. If a result would be larger than the original, Asset Compressor keeps the original file untouched, so you never end up with a bigger file.
Choosing the right JPEG quality
80–85% is the sweet spot for websites, blogs and online stores. 70% works well for thumbnails and social previews. Use 90% or higher for prints and portfolios where every detail matters.
Not sure? Compress with the default, then open any image in the before/after comparison and zoom in on fine detail such as hair, text or foliage.
Why MozJPEG?
MozJPEG is Mozilla’s improved JPEG encoder. It uses smarter quantization and progressive encoding to produce files that are typically 5–10% smaller than standard encoders at the same visual quality – and the results still open in every app, browser and device.
Frequently asked questions
Is JPEG compression lossless?
No. JPEG is a lossy format, so re-encoding discards some detail. At 75–85% quality the loss is very hard to see, which is why this range is the standard for the web. If you need zero loss, keep your originals or use PNG.
Does compressing a JPEG remove EXIF data?
Re-encoded images do not keep EXIF metadata such as camera model or GPS location, which also protects your privacy. Files that Asset Compressor keeps unchanged (because they could not be made smaller) keep their original metadata.
Can I compress hundreds of JPEGs at once?
Yes. Select a folder or drop as many files as you like. Asset Compressor processes several images in parallel using your device’s CPU cores and lets you download everything as one ZIP.
Will my photos be rotated correctly?
Yes. The EXIF orientation from your phone or camera is applied when the photo is decoded, so compressed images display the right way up everywhere.
Related tools
JPG to WebP
Convert JPEG photos to WebP for smaller, faster-loading images at the same visual quality – in bulk and without uploading.
Compress to 100 KB
Upload forms often demand images under a size limit. Set a target and Asset Compressor finds the highest quality that fits – for every image in the batch.
Resize images
Set a maximum width or height and every image is scaled down proportionally – and compressed at the same time.
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