Image Converter & WebP Optimizer
Drop in a PNG, JPG or WebP, pick an output format and quality, and download the result — with the exact saving reported in KB. Nothing leaves your browser.
Click to upload, or drag & drop an image
PNG, JPG or WebP · processed on your device
Quality is ignored for PNG, which is always lossless.
What this tool does
It converts an image between PNG, JPEG and WebP and re-encodes it at the quality you choose. The file is read with the browser's own file API, painted onto a canvas, and written back out by the browser's encoder — so the whole operation happens on your device. Because it always re-encodes rather than copying bytes, you also get a genuine size comparison: after converting, the tool tells you the new file size and how much smaller it is than the original.
Two honest limits. First, this does not resize: the output keeps the original pixel dimensions, so a 4000px photo stays 4000px and only the compression changes — that is the right behaviour for quality, but it will not rescue a file that is simply too large in dimensions. Second, the browser's encoder is not a specialist optimiser: dedicated tools using mozjpeg, oxipng or avifenc will usually beat it by another 5–15%. What you get here is a fast, private conversion that is good enough for almost every web use case.
How to use it
- Click the drop zone to choose a file, or drag an image onto it. PNG, JPEG and WebP are accepted.
- Pick the target format. WebP is the right answer for the web almost every time.
- Drag the quality slider. 75–85 is the sweet spot for photos; below 60 the artefacts start to show, and above 90 the file grows fast for very little visible gain.
- Click Convert & Download. The converted file saves immediately, and the size change is reported above the controls.
- If the result came out larger than the original — which happens when converting an already-optimised JPEG to a high-quality WebP — lower the quality and convert again.
Common use cases
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Speeding up a website
Convert hero images and blog photos to WebP to cut page weight and improve Core Web Vitals.
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Meeting an upload limit
Drop the quality until a screenshot or scan fits under a form's maximum file size.
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Preparing product photos
Normalise a folder of mixed PNG and JPEG assets into one consistent web format.
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Handling confidential imagery
Convert client mockups, ID scans or unreleased artwork without uploading them to a stranger's server.
Frequently asked questions
Is my image uploaded to a server?
No. The file is read with the browser's FileReader, drawn onto a canvas, and re-encoded on your own device. Nothing is transmitted, so the tool is safe for confidential screenshots, client artwork and unreleased product photos.
Which format should I choose?
WebP is the best default: it is typically 25–35% smaller than JPEG at the same visual quality and supports transparency. Choose JPEG for maximum compatibility with older software, and PNG only when you need lossless quality or transparency in a tool that cannot read WebP.
Why did my transparent PNG get a white background?
JPEG has no alpha channel, so transparency has to be resolved to something. This tool fills transparent areas with white rather than black, which is what most people expect. Convert to WebP or PNG instead if you need to keep the transparency.