What does this tool do?
Image Compressor shrinks JPG, PNG and WebP files with a quality slider and instantly shows the before/after file size plus the percentage you saved. You download the result in one click and your image is never uploaded. All compression runs on canvas in your browser, so it stays completely private.
How to use it
- Adjust the values and options.
- See the result in the live preview.
- Copy the generated CSS/code into your project.
What it solves
Large images slow your pages down, bloat storage and blow past upload limits. As you move the quality slider this tool re-encodes the file and typically cuts the size by 50-80% with loss that is usually invisible. The before/after comparison lets you find the smallest size without ruining sharpness.
Best format for the web
For photos, WebP produces noticeably smaller files than JPG at the same quality and is supported by every modern browser. For graphics that need transparency, lossless PNG or WebP fits best. Keeping busy photos as JPG/WebP and flat-color logos or screenshots as PNG gives the best balance.
Frequently asked questions
What is lossy vs lossless compression?
Lossy compression (JPG, WebP) permanently discards some image data to make much smaller files, which is ideal for photos. Lossless compression (PNG) keeps every pixel but produces a larger file, which suits sharp-edged graphics and transparency.
How much can I compress without visible loss?
For most photos, dropping the quality to around 0.7-0.8 (70-80%) shrinks the file dramatically with almost no visible loss. Use the before/after preview to find the sweet spot for each individual image.
Is Image Compressor free?
Yes. Image Compressor and all 300+ tools on MagmaNex are completely free with no signup or account required.
Is my data safe?
Yes. Everything runs locally in your browser. The data you enter is never sent to a server, stored, or shared.
Does it work on mobile?
Yes. Image Compressor works on phones, tablets and desktops — no app download needed.
🔒 Privacy: everything runs in your browser, your data is never sent to a server.