Image Compressor
Shrink JPG, PNG and WebP files without uploading them. Runs in your browser.
About this image compressor
This image compressor makes JPG, PNG and WebP files smaller so they load faster and fit under upload limits. Drop in one photo or a whole folder, pick a quality level, and download the results one by one or together as a ZIP file.
Everything runs inside your browser. Your images are never uploaded to a server, so private photos, scans and client work stay on your device. There is no sign-up, no watermark and no daily limit on how many files you can compress.
PNG files get real compression too. Instead of saving the same PNG again, the tool reduces it to a smart palette of up to 256 colors, which often cuts the size by more than half while keeping transparency intact.
Features
Batch compression with ZIP download
Add as many images as your device can handle. They are compressed one after another, and you can download every result in a single ZIP file.
Quality slider for JPG, WebP and AVIF
Choose a quality from 1 to 100. The default of 75 gives a large saving with little visible change. Results update by themselves shortly after you move the slider.
Lossy PNG with transparency
PNG output is reduced to 256, 128, 64, 32, 16 or 8 colors with optional dithering for smooth gradients. Transparent areas stay transparent. Images that already use few colors are kept pixel for pixel.
Before and after comparison
Pick any finished file and drag the slider across the preview to compare the original with the compressed version at the same spot.
Optional resize while compressing
Set a maximum size such as 1920 or 1280 pixels for the longest side. Shrinking oversized photos is often the biggest saving of all.
Never bigger than the original
If a compressed file comes out larger than the one you started with, the tool keeps your original file instead and tells you so.
Private by design
Files are processed on your device and never leave it. The compressed copies also drop EXIF data such as camera details and GPS location.
How to use the image compressor
- 1Drop, paste or choose one or more images.
- 2Pick the output format, quality and optional max size.
- 3Download each image or all of them as a ZIP.
When to use it
Upload forms with a size limit
Job portals, visa applications and school sites often reject photos over a few hundred kilobytes. Lower the quality or set a max size until the file fits.
Faster websites
Large images are the most common reason a page loads slowly. Compress hero images, blog photos and product shots before you upload them to your CMS or store.
Email attachments
Phone photos are often 3 to 8 MB each. Compressing a set of them lets you attach more pictures without hitting your mail provider's limit.
App and game assets
Developers can shrink PNG icons and sprites with the palette option and keep their transparent backgrounds.
Saving storage space
Compress an archive of screenshots or scans to free up space on your laptop or cloud drive.
Lossy vs lossless compression
Lossless compression stores exactly the same pixels in fewer bytes. You can decompress it and get the original back. PNG is a lossless format, which is why saving a PNG again rarely makes it smaller.
Lossy compression throws away detail that people are unlikely to notice. JPG, WebP and AVIF are lossy formats, and the quality setting controls how much detail is dropped. At high settings the difference is hard to see. At low settings you start to notice blocky areas and smeared edges.
This tool also offers a lossy option for PNG. It reduces the number of distinct colors, then stores the result as a lossless palette PNG. Graphics, screenshots and icons usually look the same. Photos with smooth gradients can show some banding, which the dithering option helps to hide.
JPG vs PNG vs WebP vs AVIF
Each format suits a different kind of image. Picking the right one often saves more than any quality setting.
- JPG: best for photos. Every app and website accepts it. It has no transparency.
- PNG: best for logos, screenshots, text and anything with transparency. Larger than JPG for photos.
- WebP: works for both photos and graphics, supports transparency and is usually 25 to 35 percent smaller than JPG at similar quality. All modern browsers can open it.
- AVIF: often smaller still, but slower to encode and not every browser can create it. The tool offers AVIF only when your browser can save it.
What quality setting should I use?
For photos on websites, a quality between 70 and 80 is a good balance. For images that will be printed or edited again, stay at 85 or higher. Drop to 50 or 60 only when you must hit a strict size limit.
Resolution matters as much as quality. A 4000 pixel wide photo shown in a 1200 pixel wide column wastes most of its bytes. Use the Max size option to bring it down first, then fine-tune the quality.
Why use Mavros
| Mavros | Typical upload sites | |
|---|---|---|
| Where files are processed | In your browser, on your device | Uploaded to a remote server |
| File count and size limits | None, apart from your device's memory | Often 20 files or 5 MB per file on free plans |
| Account or sign-up | Not needed | Often required for larger batches |
| Quality control | Quality slider, PNG colors and max size | Often a single automatic setting |
| Before and after preview | Built-in compare slider | Often only a size figure |
| Location data in output | EXIF and GPS data removed | Varies by site |
Tips
- Use the compare slider and zoom in your browser to check fine details such as text and faces before you settle on a quality.
- If a PNG photo stays large, switch the output format to JPG or WebP. Photos compress far better in those formats.
- Keep the original files. Compressing an already compressed JPG again lowers its quality each time.
- For logos and icons with only a few colors, try 64 or 32 colors with dithering turned off for the cleanest edges.
- Set Max size to 1920 px for full-width website images and 1280 px for blog content images.
Questions
Are my images uploaded anywhere?
No. The compression runs in your browser using your device's own processor. Your files never leave your computer or phone, and nothing is stored after you close the page.
How do I compress an image without losing quality?
Keep the quality at 80 or higher for JPG and WebP, and leave Max size set to Don't resize. For graphics, PNG with 256 colors usually looks identical. Use the compare slider to confirm.
Why didn't my PNG get much smaller?
Photos stored as PNG are hard to shrink because PNG is built for flat graphics. Switch the output format to JPG or WebP for photos. For graphics, try fewer colors such as 128 or 64.
How can I reduce an image to 100 KB or 200 KB?
Lower the quality step by step and watch the size shown next to each file. If it is still too large, set Max size to 1280 or 1024 px. Smaller dimensions reduce the size fastest.
Does compression keep transparency?
Yes for PNG, WebP and AVIF output. JPG has no transparency, so transparent areas become white if you choose JPG.
Is there a limit on the number or size of files?
There is no fixed limit. Very large batches or huge images depend on your device's memory. Images bigger than about 16.7 megapixels are scaled down to fit browser canvas limits, and the file row tells you when that happens.
Can I compress animated GIFs?
Not as animations yet. The tool keeps only the first frame and warns you when a file is animated.
Can I compress HEIC photos from an iPhone?
Only in browsers that can open HEIC, such as Safari. In other browsers you will see a message. You can set your iPhone to save JPG under Settings, Camera, Formats, Most Compatible.
Is the photo's EXIF data kept?
No. Compressed files are saved without EXIF data, which removes camera details and GPS location. When the original is kept because it was already smaller, that file is unchanged.