Image Format Converter

Convert between image formats locally, and see which one is actually smallest.

Drop an image here, or click to browse Converted on your device, never uploaded

The image is decoded and processed by your own browser. It is never uploaded, and no copy of it exists anywhere but this tab, you can confirm that in the DevTools Network tab while you work.

Choose an image to convert.

Size in every formatClick a row to switch to that format
Preview
Converted image preview

Features

  • PNG, JPEG, WebP and BMP output
  • Size comparison across every supported format
  • Transparency detection with a configurable matte colour
  • Quality control for lossy formats
  • Nothing is uploaded

How to use it

  1. Drop in the image you want to convert.
  2. Check the comparison table to see which format is smallest.
  3. Pick a format and adjust quality if it is lossy.
  4. Download the converted file.

Choosing a format

The old rule was PNG for graphics, JPEG for photographs. WebP has largely superseded both: it does lossy and lossless compression, supports transparency and animation, and is typically 25% to 35% smaller than JPEG at equivalent quality. Every current browser supports it. AVIF is smaller still, often another 20% below WebP, though encoding is slower and browser support, while now broad, is not universal.

The important thing to understand is that converting a lossy image to a lossless one does not restore quality. Converting a JPEG to PNG produces a larger file containing exactly the same visible artefacts, because the information JPEG discarded is permanently gone. The PNG is faithfully reproducing a degraded image. Only convert to a lossless format if you started from one.

Transparency is the other trap. JPEG has no alpha channel, so any transparent pixel must be composited against something, this tool uses the matte colour you choose, defaulting to white. Without that step transparent areas typically turn black, which is a common and jarring surprise. BMP is included mainly for completeness: it is essentially uncompressed, so files are enormous, and it is only worth using for legacy systems that require it.

Frequently asked questions

Yes, completely. Image Format Converter is free with no usage limits, no account and no sign-up. There is no paid tier and no trial that expires. Tools marked Premium on this site carry that label to indicate a deeper feature set, not a price.
Image Format Converter covers pNG, JPEG, WebP and BMP output, size comparison across every supported format, transparency detection with a configurable matte colour, among other things. Everything is available immediately with no account, no sign-up and no usage limit.
The old rule was PNG for graphics, JPEG for photographs. WebP has largely superseded both: it does lossy and lossless compression, supports transparency and animation, and is typically 25% to 35% smaller than JPEG at equivalent quality. Every current browser supports it. AVIF is smaller still, often another 20% below WebP, though encoding is slower and browser support, while now broad, is not universal.
Your image is decoded and processed by your own browser using the File and Canvas APIs. It is never uploaded, there is no server to receive it. You can verify this by opening your browser's developer tools, switching to the Network tab, and watching while you use the tool: you will see no request carrying your file. Because nothing depends on a server, the tool also keeps working offline once the page has loaded, the site registers a service worker that caches it after your first visit.

Related tools

Further reading

📖 PNG, JPG, WebP: How to Convert Between Image Formats

Read the full guide on the 123MiniApps blog.

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