How to use Compress Image
- Choose an image or drag it onto the upload area.
- Set the quality level and output format. Lower quality produces a smaller file.
- Select Compress image, check the size difference, then download.
Why compress images
A photo straight from a modern phone is usually 2 to 6 MB. That is far more than most uses need. Online application forms often limit photos to 100 KB, 200 KB or 500 KB, email attachments slow down above a few megabytes, and websites load noticeably faster with smaller images. Compression keeps the image looking the same to the eye while removing detail you cannot see, which brings the file size down dramatically.
How compression works
JPG and WEBP use lossy compression. They divide the image into small blocks and store the visual information that matters most, discarding fine variations the eye barely notices. The Quality slider controls how much is kept: higher values keep more detail and create larger files, lower values create smaller files with more visible artifacts, such as blockiness in smooth skies.
PNG uses lossless compression, which keeps every pixel exactly. That is ideal for screenshots, logos and graphics, but it cannot make a photo much smaller. To shrink a PNG photo, save it as JPG or WEBP instead.
Recommended settings
| Goal | Format | Quality | Also reduce dimensions |
|---|---|---|---|
| Website or blog photo | WEBP or JPG | 70 to 80 | Longest side 1600 to 2000 px |
| Email or messaging | JPG | 75 | Longest side 1600 px |
| Form with 200 KB limit | JPG | 70 to 80 | Longest side 1200 px |
| Form with 100 KB limit | JPG | 60 to 70 | Longest side 800 to 1000 px |
| Keep for printing | JPG | 90 to 95 | No |
How to reduce a photo to under 100 KB or 200 KB
- Open the photo and set Output format to JPG.
- Set Quality to 75 and select Compress image. Check the new size in the result.
- If it is still too large, turn on Also reduce dimensions and set Longest side to 1200 pixels. Compress again.
- For a 100 KB limit, lower the longest side to 900 or 800 pixels and quality to around 65.
- Open the result at full size to check that faces and text are still clear, then download.
Some forms count 1 KB as 1,000 bytes and others as 1,024 bytes. Aim a few kilobytes under the limit to be safe.
Checking the result
After compression, the tool shows the new file size and how much smaller it is than the original. Use the Original and Result buttons above the preview to compare, and Open full size to inspect detail. If the result is not smaller, the original was already well compressed; the tool says so, and it is usually best to keep the original.
Frequently asked questions
How much smaller will my image get?
It depends on the image. Photos saved by a camera or phone at maximum quality often shrink by 50 to 80 percent at a quality level of 75 to 80 with little visible difference. Images that were already compressed may shrink only slightly. The tool shows the exact result before you download.
Why did my PNG barely change in size?
PNG is a lossless format, so it has no quality setting to lower. To reduce the size of a PNG photo, choose WEBP or JPG as the output format. Keep PNG if you need pixel-exact graphics or transparency in software that does not support WEBP.
What quality level should I use?
For photos on a website, 70 to 80 is a good starting point. For images you plan to print or edit further, stay at 90 or above. Compare the preview at full size before downloading.
Is my image uploaded anywhere?
No. Compression runs in your browser using its built-in image encoder. The file never leaves your device.
Does compressing change the dimensions?
Only if you turn on Also reduce dimensions. Otherwise the width and height stay exactly the same.
Can I compress many images at once?
The tool works on one image at a time so you can check each result. After downloading, select Process another image; your settings are kept.
Is WEBP accepted by government and university websites?
Not always. Many upload forms accept only JPG or PNG, so use JPG for forms unless WEBP is listed.