Image Compress
Batch-compress image size online for PNG, JPG and WebP, either by quality or by smartly targeting a specific file size, output WebP / JPG to save more space, with optional proportional resize. Shows before/after size comparison in real time, fully local in your browser with no uploads.
Features
- Batch-compress common formats such as PNG / JPG / WebP
- Two modes: compress by quality, or smartly approach a target size (KB)
- Output WebP / JPG for smaller size, or keep the original format
- Optional proportional resize to limit max width/height and further reduce size
- Real-time before/after size and compression ratio, per image and overall
- Single or one-click ZIP download, fully local with no uploads
FAQ
Are my images uploaded to a server?
No. Image decoding, compression, resizing and packaging all happen locally in your browser — files are never uploaded to any server, secure and fast.
How does "target size" work?
The tool uses binary search to automatically adjust the compression quality, encoding multiple times to approach your target size (KB). If the target is very small, it gets as close as possible while keeping usable quality.
Why is PNG compression not very effective?
PNG is lossless, so re-encoding rarely reduces size much. If transparency is not needed, output as JPG; if it is, choose WebP, which usually offers better compression.
Will quality drop after compression?
JPG / WebP are lossy — lower quality means smaller size but more visible quality loss. Use the preview and size comparison to pick a suitable quality that balances clarity and size.