About This Tool
Image File Size Reducer helps meet attachment or upload size limits. Set a target size and minimum quality, then choose whether resizing is allowed. The result lists the quality and pixel dimensions used.
How to Use
- Choose an image, enter the target size, and select KB or MB.
- Choose JPG or WebP output and a minimum quality. Decide whether to allow resizing if needed.
- Click “Optimize to target size” and wait for processing to finish before making further changes.
- Check the actual file size, quality, and dimensions before downloading. If the target was not met, follow the guidance to adjust your settings.
Settings explained
- The target must be greater than 0 and no more than 100 MiB. KB and MB are supported: 1 KB = 1,000 bytes and 1 MB = 1,000,000 bytes.
- Minimum quality defaults to 20%. It sets the lowest quality you are willing to accept to meet the target.
- “Allow resizing if needed” is enabled by default. Turn it off to keep the original dimensions throughout.
Supported Formats
- Input: JPG/JPEG, PNG, or static WebP.
- Output: JPG or WebP, with quality adjusted based on actual file sizes.
Image Processing Notes
The tool compares actual file sizes at different settings. Pixel dimensions are reduced only when resizing is allowed and the original dimensions still exceed the target at minimum quality. The result lists the final quality and dimensions.
Each image can be up to 100 MiB. Files over 50 MiB trigger a high-memory-use notice. Original and output images are limited to 16 megapixels, with each dimension no greater than 16,384 pixels. Some operations have lower limits; resize the image first if prompted.
Compression and image quality
- The tool tries several quality levels and compares actual sizes, aiming for a usable result at or below your target. Results depend on the image and are not guaranteed to match an exact byte count.
- This page outputs JPG or WebP and uses quality adjustments to approach your target size. PNG input can also be saved in either format.
- Dimensions are reduced gradually only if the image is still too large at minimum quality and you have allowed resizing.
- Resizing reduces pixels and detail. The result clearly lists the original and final dimensions.
- If the target cannot be met within the available attempts and dimension limits, the tool tells you so you can adjust the target, format, or minimum quality.
- PNG and WebP support transparency. JPG blends transparent areas with your chosen background color, which is white by default. The preview’s checkerboard is not included in the download.
- Downloads contain the full processed image. Saving again can change file size and compression details, and usually removes original EXIF, GPS, and similar information. Keep your original file.
Privacy
Images are processed entirely in your browser and are never uploaded to a server.
Files are not saved automatically. Download any results you want to keep before clearing or leaving the page, and keep your original file.
FAQ
Can I compress to exactly 500 KB?
An exact size of 500,000 bytes is not guaranteed. File size varies by image and format. The tool aims to get close without exceeding the target; check the final result.
Why is resizing sometimes necessary?
A large image may exceed the target even at the lowest allowed quality. Allowing fewer pixels can reduce the file further, but also removes detail.
What is the difference between quality and resolution?
Quality affects compression when saving. Resolution is the image’s width and height in pixels. Lowering quality usually keeps dimensions; resizing reduces the pixel count.
Which format is best for a smaller file?
JPG and WebP often work well for photos. Try WebP for transparency. Lossless PNG usually needs more space, though icons with few colors can be very small.