Image Converter: PNG, JPG, WebP and SVG, Resize and Compress

  • Free
  • No sign-up
  • Runs in your browser
  • Version 1.1.0
  • Last updated 2026-10-07
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Convert, resize and shrink images right in your browser. Your photos never leave your device.

Everything you enter is processed in your browser and is never sent to a server.

How to use

  1. Drop images onto the box or choose files. You can add up to 50 at once.
  2. Pick the format to convert to. For JPG, WebP and AVIF, move the quality slider: lower means a smaller file. Optionally choose a new size.
  3. Download each converted image, or all of them as one ZIP.

Examples

My Photo.PNG, convert to WebP
→ My Photo.webp
Only the extension changes; the name is kept.
4000×3000 photo, set width 1200
→ 1200×900
Setting only the width or only the height keeps the proportions.
1920×1080 image, scale by 50%
→ 960×540

How it works

The browser opens each file and hands over its pixels. Resizing uses the Lanczos filter from the jSquash resize package, and saving uses the codecs of Google’s Squoosh app, compiled to WebAssembly: MozJPEG for JPG, libwebp for WebP, libavif for AVIF, and the PNG encoder with OxiPNG for smaller PNG files. These usually give smaller files at the same visual quality than the browser’s own encoders, and the same result in every browser. A size set by width or height alone keeps the aspect ratio, rounding to the nearest pixel. An SVG is drawn at the final size, so it stays sharp.

Quality applies to JPG, WebP and AVIF only. Each codec is downloaded the first time you use its format, so the page stays light until then.

The ZIP is made by the fflate library. Images are already compressed, so files are stored without further compression, and names that repeat get -2, -3 added.

The size calculations, file naming and SVG size detection are tested, and so are the codecs: JPG, WebP and PNG output is checked for valid file headers, lower quality is checked to give a smaller JPG, OxiPNG is checked not to grow a PNG, and resizing is checked for the exact output size.

Sources

Frequently asked questions

Are my images uploaded to a server?
No. Each image is decoded and re-encoded by your browser, and the result stays on your device. You can check this by turning off your network connection after the page has loaded; the tool keeps working.
Which format should I choose?
Use AVIF or WebP for the smallest files on the web, JPG for photos that must open everywhere, and PNG for screenshots, logos and anything that needs sharp edges or transparency. PNG is lossless, so its quality slider does not apply and its files are larger. AVIF is the smallest but the slowest to make, and a few older apps cannot open it.
What happens to transparency?
PNG, WebP and AVIF keep it. JPG has no transparency, so transparent areas are filled with the background color you choose, white by default.
Does the photo's location data stay in the file?
No. The image is redrawn, so camera details, GPS location and other metadata are not copied to the result. The picture is rotated to match how it was meant to be viewed.
Can I convert SVG?
Yes. An SVG is drawn at its own size, or at the size you set, and saved as PNG, JPG, WebP or AVIF. Because it is a vector, a larger size stays sharp. The tool cannot save to SVG.
Why can the file get bigger?
Converting an already compressed JPG to PNG, or raising the quality, can increase the size. The list shows the before and after size for every image so you can see it.
What are the limits?
Up to 50 images at a time, and results of up to 50 million pixels (for example 8000×6000) because phones run out of memory beyond that. HEIC and animated images are not supported; a GIF is converted from its first frame. AVIF files take longer to make than the others.
Version history
  • 1.1.0 — Converts with the Squoosh codecs (MozJPEG, libwebp, libavif, OxiPNG) and Lanczos resizing; adds AVIF output.
  • 1.0.0 — First release.

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