Image Compressor
Compress images in bulk online with an adjustable quality slider and an optional longest-edge limit, compare the before and after file sizes at a glance, and download everything as a ZIP.
FreeOnline Tool
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How to Use
- Click the upload area to choose images, or drag several onto the page; batch upload is supported.
- Pick an "Output format" in the toolbar: keep the original format, or force JPEG, WebP or PNG.
- Drag the "Quality" slider to set how hard the images are compressed. Lower values mean smaller files and more visible quality loss (this applies to JPEG and WebP only).
- To shrink the dimensions too, tick "Limit longest edge" and enter a pixel value; any image larger than that is scaled down proportionally.
- Every image is re-compressed automatically whenever you change a setting, and the list shows the original size, compressed size and percentage saved in real time.
- Click "Download" on a single image to save it on its own, or "Download all as ZIP" to get every result in one file.
Click "Load sample images" to try batch compression straight away without preparing your own files.
Features
- Batch compression: drop in several images at once, apply one set of settings to all of them, and add or remove files at any time.
- Live size comparison: each image shows its original size, compressed size and percentage saved, so the effect is obvious.
- Adjustable quality: JPEG and WebP support a 10%-100% quality slider; PNG is a lossless format, so for PNG the saving comes mainly from scaling.
- Longest-edge limit: optionally scale oversized images down proportionally to reduce file size further.
- ZIP download: a built-in front-end ZIP packer lets you download every compressed image in one click instead of saving them one by one.
- Local processing: images are handled entirely inside the browser and never uploaded, so your privacy is preserved.
Use Cases
Optimizing images for a website
Compress site images in bulk before uploading them to cut page weight and speed up loading.
Slimming down email attachments
Compress a batch of photos before attaching them so the message stays under the attachment size limit.
Archiving a photo library
Batch-compress photos exported from a phone to save space locally or in cloud storage.
Preparing images for social platforms
Bring files under a platform's size limit to avoid failed uploads or the quality loss of a second round of compression.
FAQ
Does compression reduce image quality?
With JPEG or WebP and a quality slider below 100% there is some lossy compression. PNG is lossless, so quality is untouched, but the size reduction is limited; choose JPEG or WebP when you need a noticeably smaller file.
Why does the size barely change when I pick PNG?
PNG is a lossless format. In this tool PNG output is mainly there to work with the "Limit longest edge" option to shrink dimensions; it cannot cut file size through a quality setting the way JPEG and WebP can.
Are the images uploaded to a server during batch compression?
No. Every image is compressed locally in your browser with Canvas, nothing is sent anywhere, and you can simply close the page when you are finished.
Do I need extra software to open the ZIP download?
No. It is a standard ZIP file that the built-in extraction tools in Windows and macOS can open directly.