Reduce image file size by re-encoding JPG, PNG or WebP in your browser. Compare the original and output sizes, choose a quality level, or try an approximate target such as 100 KB, 200 KB or 500 KB for JPEG and WebP. Inspect the downloaded file before using it in a form with a strict upload limit.
lightbulb When to use this tool
- check_circle Prepare a photo for a form with a file-size limit, then verify its actual downloaded size.
- check_circle Compare image quality and byte size before publishing images on a website.
- check_circle Process several images and collect the results in a ZIP.
Inputs and results
Input: JPG, PNG or WebP images, an output format, and either a quality level or an approximate target size in KB.
Output: Processed images with size comparisons, individual downloads and an optional batch ZIP.
Why use our tool?
Compare actual file sizes
Original and processed sizes let you judge the actual result.
Choose quality or target size
Quality and target-size modes serve different tasks: visual control or an approximate size goal.
Resize when quality is insufficient
The companion Image Resizer provides the next step when the image has more pixels than needed.
How it works
Add one or more images and choose the output format.
For a JPEG or WebP size goal, enable Target File Size and enter the limit in KB; for visual control, adjust Quality instead.
Compress and compare the result with the original. Check both image appearance and actual file size.
If the result is still too large, resize the image to smaller pixel dimensions with Image Resizer and compress it again.
Download the image or batch ZIP. For a strict form limit, leave room below the stated maximum and check the form's format and dimension rules too.
Examples
science Prepare a photo for a 200 KB form limit
Choose JPEG or WebP and try a target of 200 KB. If the downloaded result is above the form's limit, try a lower target or resize the dimensions first. A target setting alone does not prove the file will be accepted.
science Separate pixels from file size
A 2400 × 1600 photo has 3,840,000 pixels. Resizing it to 1200 × 800 leaves 960,000 pixels, one quarter as many. The encoded byte size will not necessarily be exactly one quarter, because image detail and format also affect compression.
Limitations
A target size is an estimate, not a guarantee that output is below the limit. PNG encoding ignores the quality setting, so use JPEG or WebP for quality-based target compression. Pixel dimensions are not reduced here; use Image Resizer if lowering quality is insufficient. Re-encoding can remove metadata and animation. Results vary by image and browser.
Frequently Asked Questions
Can I compress a photo to exactly 100 KB or 200 KB? expand_more
Why does changing quality have little effect on PNG? expand_more
Does compression change image width and height? expand_more
Why is my already optimized image not getting smaller? expand_more
Processing & Privacy
Processing uses your browser rather than uploading the supplied input to a processing server. Fonts and tool libraries can make third-party network requests. Optional analytics loads after consent. See the Privacy Policy for site-wide details.