Practical guide
How to use Image Compressor
Image Compressor reduces the size of a selected image by re-encoding it as JPEG or WebP with adjustable quality. It is intended for web uploads, messages, documentation, and other cases where a smaller file matters more than lossless preservation.
Step by step
- Choose an image and select JPEG or WebP.
- Adjust quality, then compress and compare the original and result sizes.
- Inspect the preview at useful zoom levels before downloading the smaller file.
Example
2.4 MB JPEG at quality 78A new JPEG or WebP with its measured size and percentage changeHow it works
The browser decodes the source, draws it to a Canvas at its original dimensions, and encodes new bytes using the selected format and quality setting.
Important limitations
- Compression can introduce blur, ringing, banding, or color shifts.
- A small or already optimized image may become larger after another conversion.
Real workflows
When this tool is useful
Website delivery
Reduce a photograph before publishing it to improve transfer size while comparing visible detail at the actual display dimensions.
Email and chat
Create a smaller copy that fits an attachment limit without overwriting the high-quality source file.
CMS preparation
Test JPEG or WebP quality levels locally before uploading an asset into a content system that may apply another compression pass.
Review the result
What to check before using the output
Compare file size and image quality at 100 percent zoom and at the intended display size. Watch text, line art, gradients, transparency, and already-compressed images for disproportionate damage.
- Preserve the original file.
- Resize oversized images before quality tuning.
- Compare at the final display size.
- Avoid repeated lossy re-encoding.
Choose the right method
When another tool is better
Resize first when pixel dimensions are much larger than the destination. Use a professional optimizer for animated formats, lossless tuning, metadata policy, or repeatable build-pipeline output.
Privacy and browser behavior
Encoding happens in browser memory and the source is not sent to a 77 Toolkit server. Keep the original because re-encoding is normally lossy and cannot restore discarded detail.
Frequently asked questions
Which format should I choose?
WebP often provides smaller web files; JPEG remains widely compatible for photographs. Neither is ideal for every graphic.
Does quality change image dimensions?
No. This tool preserves width and height; use Image Resizer to change dimensions.