Image Compressor – Compress Up to 10 Images at Once
About the Image Compressor
The Image Compressor reduces the file size of up to 10 images in a single pass, letting you set one quality level, one output format, and one maximum dimension that applies to the whole batch. Each image gets its own row showing the original dimensions, source format, and byte size, then updates in place with the compressed size and exact percentage saved once processing finishes. A summary strip above the list totals everything, so you can see at a glance that a 24 MB folder of photos came down to 3 MB before you commit to downloading anything.
Compression happens through the Canvas API in your browser. Each image is redrawn at the target dimensions and re-encoded at your chosen quality, which means no file leaves your device and there is no queue or rate limit to wait on. The uploader accepts effectively any image your browser can display, including JPG, PNG, WebP, GIF, AVIF, TIFF, and BMP, and it also handles HEIC and HEIF photos from iPhones by decoding them first. Output is written as JPEG, PNG, or WebP.
Two details worth knowing before you start. The quality slider only affects JPEG and WebP output, because PNG is a lossless format and ignores a quality value entirely; PNG savings come from resizing and from re-encoding, not from the slider. And the Max Dimension setting only ever shrinks, never enlarges, so a 900px image stays at 900px even if you select Full HD.
Most size reduction on a real website comes from resizing rather than from quality alone. A 4000px camera photo displayed in a 800px content column is carrying about twenty-five times more pixel data than it needs, which is why the Max Dimension dropdown usually does more work than the slider. If your photos are still sitting in HEIC format straight off a phone, the HEIC Image Converter handles that conversion with more control over the output format.
Our testing team at BigToolSite ran this compressor against 10-image batches of DSLR JPEGs, transparent PNG logos, animated GIFs, screenshots, and iPhone HEIC photos, confirming that the 10-image cap and the 10MB per-file limit both reject cleanly with a named error, and that re-running Compress All with new settings correctly replaces the previous result rather than stacking blobs in memory.
For a single image where you want fine control over dimensions and a wider set of output formats, the PNG Image Converter is the better fit than a batch tool.
If you are compressing specifically to improve Largest Contentful Paint, WebP is usually the format to target, and the WebP Image Converter covers single-file conversions with more format options on both ends.
How to Use the Image Compressor
- Drag between 1 and 10 images onto the upload area, or click to browse and multi-select. Each file can be up to 10MB.
- Review the list. Every image shows a thumbnail, filename, pixel dimensions, detected format, and original size, with a status line reading “Ready to compress”.
- Set the Quality slider between 10% and 100%. The default is 75%, which is a practical starting point for photographs. This applies to JPEG and WebP output only.
- Choose an Output Format: JPEG for the smallest photo files, PNG for lossless output, or WebP for modern browsers.
- Pick a Max Dimension: No Resize, 4K (3840px), Full HD (1920px), HD (1280px), Medium (800px), or Small (500px). The longest side is capped at that value and aspect ratio is preserved.
- Click Compress All. Each row fills a progress bar, then shows the original size struck through, an arrow, the new size in green, and the percentage saved.
- Check the summary stats for image count, original total, compressed total, and total saved across the batch.
- Download individual files with the Download button on each row, or use Download All (ZIP) to get everything as compressed-images.zip.
- Adjust any setting and click Compress All again to redo the whole batch, or use Remove on a single row and Clear All to start over.
Example Usage
Input: 6 camera photos, 4032×3024 each, 21.4 MB total
Settings: Quality 75%, Format JPEG, Max Dimension 1920px
Result: each photo resized to 1920×1440 and re-encoded, downloaded as a ZIP with filenames like DSC_0142-compressed.jpg
Because both the resize and the quality step apply, this combination typically produces the largest reduction, often showing a total saved figure well above 90% in the summary strip.
For a set of transparent PNG logos, choose PNG as the output and set Max Dimension to 500px. Transparency is preserved, and the savings come entirely from the dimension change. Choosing JPEG instead would flatten those transparent areas to a white background, since JPEG cannot store an alpha channel.
If a compressed file comes out larger than the original, that usually means the source was already efficiently compressed, for example a WebP or AVIF being re-encoded as PNG. In that case switch the output format or raise the max dimension rather than lowering quality further.
Frequently Asked Questions
Up to 10 images per batch, with each file capped at 10MB. If you drop more than that, the tool tells you how many slots are left instead of silently ignoring the extras.
No. Decoding, resizing, and re-encoding all run locally in your browser using the Canvas API, so your images never leave your device.
75% suits most photographs and is the default. Drop to 60% for thumbnails or background images where detail matters less, and stay at 85% or above for hero images and product photography where artifacts would be visible.
PNG is a lossless format, so it stores every pixel exactly and has no quality parameter to adjust. To shrink a PNG, use the Max Dimension setting or switch the output to JPEG or WebP.
Yes. Redrawing the image onto a canvas discards all metadata, including GPS coordinates, camera settings, and timestamps. Keep your originals if you need that information.
WebP usually beats JPEG at the same visual quality, often by 25% to 35%, and every current browser supports it. Choose JPEG when a file needs to open in older software or be accepted by a system that rejects WebP.
Yes, if you select PNG or WebP as the output format. JPEG fills transparent areas with white because the format has no alpha channel.
Only the first frame is compressed. The output is a static image, so use a dedicated video or animation tool if you need to keep the motion.
Yes. Adjust the quality, format, or dimension and click Compress All. Every image is reprocessed from its original file, not from the previous compressed version, so quality does not degrade with each pass.
