Who this helps
- People preparing photos for forms, email or blog posts.
- People checking whether a transparent logo becomes smaller after conversion.
Image Utility
Image Compressor
Convert JPG, PNG and WEBP in your browser. The original file is neither sent to the server nor overwritten, and its EXIF data is not copied to the result.
Browser Compression
Process images in your browser without uploading them to the server.
Quality Control
Adjust compression quality and maximum image width.
Format Conversion
Choose JPG, PNG, or WEBP as the output format.
Upload Image
Upload a JPG, PNG, or WEBP image, then set the compression quality and output format.
Notice
A new file is created without changing the original. Original EXIF and location data are not copied. Animated images are saved as still images.
Compression Settings
Adjust quality, size, and output format, then compare the original image with the compressed result.
Original Image
No image has been uploaded yet.
Compressed Result
The compressed result will appear here.
Upload an image, then press the Compress button.
Compress images for an upload limit without losing useful detail
File size, pixel dimensions and image quality are separate decisions. Use a suitable width first, then compare JPEG or WebP quality. The sample measurements below come from the existing Windows Chromium 153 check on 2026-09-20; they describe those files only.
When to use this tool
- Reduce a large photo to the width needed by a page.
- Compare a compressed output with an already optimized original before replacing it.
From input to a checked result
- 1
Choose a JPEG, PNG or WebP file: at most 25 MiB, 24 million pixels and 12,000 pixels per side.
- 2
Set a maximum width, or leave it blank to keep the original size. Small originals are not enlarged.
- 3
Compare JPEG or WebP quality from 10 to 100; the default is 82. PNG does not use this quality control.
- 4
Keep transparency with PNG or WebP. JPEG and outputs with transparency disabled use a white background.
- 5
Compress, check the output size and fine details, then download. Changing the settings requires another conversion.
Large photo, smaller width
- Input
- pattern.jpg: 1600×1200, 2,483,967 bytes; JPEG, width 800, quality 82
- Result
- 800×600, 186,373 bytes; 92.5% smaller in the recorded check.
The central text remained readable, while fine patterns showed compression artifacts. This is a reproducible sample, not an expected saving for every photo.
A small PNG can become larger
- Input
- alpha.png: 256×192, 1,037 bytes; PNG at the original dimensions
- Result
- 2,443 bytes; 135.6% larger, with the transparent corner retained.
Canvas re-encoding can lose the original file's compact encoding. Keep the original if it is smaller and already meets your needs.
Transparency and file size are different properties
- Input
- alpha.webp: lossless 256×192, 318 bytes; WebP quality 82
- Result
- 2,068 bytes with transparency; 1,762 bytes with a white background.
Preserving alpha does not make WebP color compression lossless. The original was smaller than either output.
How it works
The tool draws the decoded image onto a canvas, preserves its aspect ratio and rounds the new height to a whole pixel. It exports a Blob and checks the actual output format. The size change is calculated from the original and output byte counts; displayed KiB use 1,024 bytes.
Limitations
- A quality number is an encoder setting, not a percentage of the original size.
- Animated images become a still frame. Color profiles and HDR appearance are not guaranteed.
- Canvas export does not preserve all original metadata. The recorded orientation check covered one EXIF-orientation-6 JPEG only.
- The tool does not automatically target an exact KB limit.
Your data
The selected image is processed in browser memory. This tool does not send the original or output image to the win-j server.
References
Related tools
- Image Resizer
Set pixel dimensions when the destination specifies a width or height.
- Image Format Converter
Compare formats when transparency or compatibility is the main concern.
Frequently asked questions
How can I get a photo under 100 KB?
Check the destination's minimum pixel dimensions first. Reduce unnecessary width, then try lower JPEG or WebP quality and check the result each time. Exact-size targeting is not available. A site may mean 100,000 bytes by 100 KB, while 100 KiB means 102,400 bytes.
Why is the PNG quality slider disabled?
This tool does not apply the JPEG/WebP quality setting to PNG. Try smaller dimensions, or compare another format that preserves what you need.
Why did compression make the file larger?
The original may already be highly optimized. Compare actual bytes and keep the original if it is smaller; an output file does not have to replace it.
Does WebP keep a transparent background?
Yes, when transparency is enabled and the browser exports WebP successfully. Check the output format and preview before downloading.