Image Compressor for JPG, PNG and WebP Files
Reduce image file size for faster websites, emails and uploads. Compress JPG, PNG and WebP images in batches, aim for a target size, convert to WebP if you want, and download each file or a ZIP. Your images are processed in your browser and are not uploaded to our server.
How This Image Compressor Reduces File Size
The compressor re-encodes each image at a lower quality, optionally resizes it, and keeps whichever result is smallest without being visibly worse. You choose the format, quality or target size, then download the files one by one or together as a ZIP.
Every photo straight from a phone or camera carries far more data than a web page needs. A typical smartphone photo is several thousand pixels wide and several megabytes in size, while the space it fills on a website might be 1,200 pixels wide. Sending the full file makes pages slower, uses visitors’ mobile data and can drag down Core Web Vitals scores such as Largest Contentful Paint.
This tool works in three ways at once. First, lossy formats such as JPG and WebP let you trade a small amount of detail for a much smaller file, and the quality slider controls that trade-off. Second, the optional maximum width scales oversized images down to a sensible size. Third, the optional target size runs a search: it tries different quality levels to find the highest one that fits your target, and only reduces the dimensions if quality alone is not enough.
If you want to change the format without any compression thinking, our PNG, JPG and WebP converter is the simpler choice.
Compressing Images in Four Steps
- Add your images. Drag them onto the drop area or click to choose files. You can mix JPG, PNG and WebP in one batch.
- Choose an output format. Keep the original format, or convert everything to WebP for the best size on modern websites, or to JPG for maximum compatibility.
- Set quality or a target. Use the quality slider for a consistent look, or pick 50 KB, 100 KB, 200 KB, 500 KB or a custom size when a form or platform has a strict limit.
- Review and download. Compare the before and after previews, check the size and percentage saved, then download each file or the full batch as a ZIP.
Each result shows the original size, the final size, the reduction, and the original and final dimensions, so you can see exactly what changed before you use the file anywhere.
Which Format Should You Choose?
The right format depends on what the image shows and where it is going. This table summarises the practical differences.
| Format | Best for | Transparency | Compression |
|---|---|---|---|
| WebP | Website photos, banners, product images, screenshots | Yes | Lossy or lossless; usually the smallest at similar quality |
| JPG / JPEG | Photos for email, documents and older systems | No | Lossy; very widely supported |
| PNG | Logos, icons, diagrams and images that need sharp edges | Yes | Lossless; often large for photos |
When to keep JPG
Keep JPG when the image is going into an email, a document, a print workflow or a platform that does not accept WebP. A quality setting between 70 and 85 percent is a sensible starting point for most photos.
When to convert to WebP
WebP is supported by all current major browsers and is usually the best choice for images on your own website. It handles photos and transparent graphics, so it can replace both JPG and PNG in most layouts.
When to keep PNG
Keep PNG for small logos, icons and line art where crisp edges matter and the file is already small. Converting a large PNG photo or screenshot to WebP will usually save far more space than any PNG setting can.
Using a Target File Size
Many upload forms, job portals, marketplaces and email systems set a maximum file size. Choosing a target tells the compressor to aim for that limit for every image in the batch.
The tool starts at high quality and searches downwards until the file fits. If the lowest reasonable quality is still too large, it reduces the width and height in steps and tries again. When a target cannot be reached without making the image unusable, the result card says so and gives you the smallest reasonable version, rather than pretending the target was met.
Very small targets suit thumbnails and profile pictures. For a large hero image, a target of 200 KB or 500 KB will usually look far better than 50 KB.
Why Image Size Matters for SEO and Speed
Images are often the heaviest part of a page. Oversized files slow down the moment your main content appears, which affects how visitors experience the page and feeds into the page experience signals Google measures. Smaller images also cost less to serve and load faster on patchy mobile connections.
Compression is only one part of image performance. Correct dimensions, lazy loading below the fold, modern formats and caching all play a role. If your site is still slow after optimising images, our technical SEO audits look at the full picture, from render-blocking scripts to server response times.
A simple checklist before you upload
- Resize to roughly the largest width the image will actually display at.
- Use WebP for website images unless a system requires JPG or PNG.
- Check the after preview at full size for blurring, banding or blocky edges.
- Give the file a descriptive name before uploading, such as blue-office-chair.webp.
- Add meaningful alt text in your website editor.
Privacy, Safety and Honest Limitations
Compression happens in your browser. Your images are not sent to our server, and the tool does not keep any copy after you leave or refresh the page. Files are checked by their actual content, not just their extension, so renamed files and executable programs are rejected.
To keep your browser responsive, each batch accepts up to 30 images of up to 25 MB each and up to 50 megapixels per image. These are safety limits, not usage limits; you can run as many batches as you like.
Results can vary slightly between browsers because each browser uses its own image encoders. Some older browsers cannot create WebP files; when that happens the tool tells you and saves JPG instead. Animated WebP files are flattened to their first frame.
Frequently Asked Questions
Are my images uploaded to your server?
No. The images are decoded, compressed and packaged into the ZIP inside your own browser using built-in canvas features. Nothing is sent to ZTechzSolutions and nothing is stored after you close or refresh the page. The only extra download is the small ZIP library, which is fetched from a public CDN when you ask for a ZIP.
Why did one of my images get larger?
This happens when an image has already been compressed well, or when you convert a small graphic such as a logo to a lossy format. If the result would be bigger and the format and size are unchanged, the tool keeps your original instead. If you changed the format or width, try a lower quality setting or keep the original format.
Can it always hit my target size?
Not always. The tool lowers quality step by step and, if that is not enough, reduces the dimensions until the file fits. A 4000-pixel photo cannot sensibly become 50 KB without shrinking a lot, so treat the target as a best effort. The result card tells you when the target could not be reached.
Does compressing a PNG reduce quality?
PNG is a lossless format, so the browser cannot lower its quality the way it can with JPG or WebP. Keeping a PNG as PNG mainly saves space through resizing. For real savings on photos or screenshots, convert to WebP, which supports transparency, or to JPG if transparency is not needed.
Is the photo location and camera data removed?
Yes. Re-encoding through a canvas writes a fresh file without the original EXIF metadata, which includes GPS location, camera details and dates. The image orientation is applied first so photos from phones are not saved sideways.
What is a good file size for website images?
It depends on how large the image appears. As a practical starting point, many teams aim for roughly 100 to 200 KB for a full-width hero image and well under 100 KB for in-content images and thumbnails, then check that the image still looks sharp on a real screen.
Is there a limit on how many images I can compress?
There is no daily limit, account or payment. Each batch handles up to 30 images of up to 25 MB each so your browser does not run out of memory. When a batch is finished you can clear it and start another.
Need a Faster Website Overall?
Image compression is a quick win. If you want a site that loads quickly, ranks well and turns visitors into enquiries, work with our Australian web team on the rest.
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