About Compress Image
Compress Image re-encodes a picture at a quality level you choose, in either JPEG or WebP, to reduce the file size it takes to store or serve. The quality field is the lever: lower values discard more fine detail and produce a smaller file, higher values keep more of the original at the cost of size.
What it does not do is change the pixel dimensions. This is the single most important thing to understand, because it explains why a photo that has already been saved once by a camera or a phone may barely shrink — that image has already had the easy savings taken out of it. Real reductions usually come from combining a lower quality setting with a resize, and the two are separate tools here on purpose.
Two side effects come with any re-encode. The output is written by the browser rather than by the original camera software, so all metadata is dropped: capture settings, copyright fields and any location coordinates are gone, which is worth knowing whether you consider that a privacy win or a loss of information. And the filename keeps its original base with a new extension matching the chosen format.
How to use Compress Image
- 1 Choose the image to compress.
- 2 Set the quality percentage — start around 70 and lower it until the size and the appearance suit you.
- 3 Choose JPEG for broad compatibility or WebP for a smaller file at the same quality.
- 4 Download the result, which keeps the original dimensions.
Frequently asked questions
Why did my file barely get smaller?
Because compressing here does not resize. An image that has already been optimised once has little redundancy left to remove, so the quality setting can only trade visible detail for bytes. Resize first, then compress, for a substantial reduction.
What happens to the photo metadata?
It is not carried over. Re-encoding through a canvas writes a bare image with no EXIF block, so camera settings, timestamp and any location data are discarded. That strips sensitive information but also means the file no longer records how it was taken.
Which format should I choose?
WebP generally produces a smaller file than JPEG at the same visual quality and is supported by all current browsers, so it is the better default for the web. Choose JPEG when a target system or toolchain does not accept WebP.
Can I compress a PNG with this?
You can upload one, but the output is re-encoded in the format you select, so the transparency may be lost if you choose JPEG. PNG itself is lossless and has no quality setting, so re-saving it here would not reduce its size meaningfully.
Free, online, and private
Free to use
Compress Image is completely free. There is no account to create, no login, and no hidden charge or usage limit.
Runs online in your browser
It is a free online tool that runs entirely in your browser. Nothing to download or install — open the page and start using it right away.
Your data stays private
All processing happens locally on your device. Your input is never uploaded, stored, or tracked, so it never leaves your browser.
How Compress Image behaves in detail
These are the specifics of this implementation — the exact ranges, defaults and fixed settings you are working with.
| Parameter | Value |
|---|---|
| Quality mapping | the percentage is divided by 100 and clamped between 0.01 and 1 before it is passed to the encoder as its quality argument |
| Quality field | 1 to 100 percent, default 70 |
| Formats | 2 choices in the dropdown, JPEG (default) and WebP |
| Dimensions | unchanged — the canvas is created at the source image's natural width and height, so no pixel is resampled |
| Encoder | canvas.toBlob with the MIME type picked from the dropdown; every other tool on this page uses the same helper at a fixed default |
Compiled from the implementation of this tool and checked against it by itoolnet.
What Compress Image does not do
Knowing the edges of a tool saves more time than another list of its features. These are the cases where it will not do what you might expect.
- Dropping the quality is the only lever available. There is no resize, no target file size, no chroma-subsampling choice and no size readout, so whether the result is actually smaller than what you sent is something you discover after downloading.
- No PNG output is offered and no background colour is painted before the encode, so choosing JPEG discards the alpha channel with the transparent pixels resolved by whatever the encoder does rather than by a matte colour you select.
- Quality is a hint rather than a measurement: one percent does not mean a hundredth of the size, and because each run re-encodes the whole picture from scratch, compressing an already-compressed file adds another generation of artefacts.
Tested and documented by itoolnet, the team that builds and maintains this site.