Real image encoders
JPEG uses mozjpeg optimization, PNG uses high-effort palette quantization, while WebP and AVIF use their native high-effort encoders through Sharp and libvips.
All tools
Image tool · Professional encoding
Image Compressor
Genuinely reduce image file size with format-native encoders, measured results, and a detailed before-and-after inspection, not a cosmetic conversion trick.
Processed in memory, never stored
Drop images here
JPEG, PNG, WebP, or AVIF · Up to 10 files · 25 MB each
Professional image compression.
Add an image to run real format-native encoders and inspect the exact output side by side.
How it works
Real compression, with evidence.
The server decodes the original once, applies orientation and optional resizing, then runs high-effort encoders. What you see is the actual returned file, not an estimate.
- 01
Add one or more images
Choose static JPEG, PNG, WebP, or AVIF files up to 25 MB each.
- 02
Set the output
Choose compression strength, format, resize limits, and colour-profile handling.
- 03
Inspect and download
Compare the actual output, verify its dimensions and measured savings, then download it.
A serious compression pipeline
Built around output quality and actual bytes.
No estimated savings
Every result shows the file size returned by the encoder. If an attempted result is not smaller, Toolkit rejects it instead of presenting an increase as compression.
Quality you can inspect
A draggable before-and-after view makes compression artifacts visible before a file is downloaded.
Image compression questions
Formats, quality, privacy, and real savings.
Is this a real image compressor or just a format converter?+
It is a server-side Sharp and libvips optimization pipeline. Each format uses its own encoder settings, including mozjpeg for JPEG, palette quantization for PNG, and high-effort WebP and AVIF encoding. Auto mode tests suitable formats and keeps the smallest actual result.
Can compression ever make my image larger?+
The encoder may occasionally produce a larger attempt when an image is already highly optimized, but Toolkit does not return it. You will see an already-optimized message and keep your smaller original.
Which compression strength should I choose?+
Balanced is the best starting point for most photos and web images. Light keeps more detail, while Strong and Maximum trade more visual information for a smaller file.
What does Auto format do?+
Auto encodes the image in several suitable modern and source-compatible formats, measures the real byte size of each result, and returns the smallest one. Choose a specific format when compatibility or file type matters more than absolute size.
Are uploaded images stored?+
No. Images are processed in memory for the current request and returned immediately. The app does not save them to a database or permanent server storage.
Why are animated images not accepted?+
This tool currently focuses on high-quality static image optimization. Rejecting animation prevents a multi-frame image from being silently flattened into one frame.
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