Click to choose, or drop an image here
You can also paste with Ctrl+V · dropping anywhere on the page works
PNG / JPEG / WEBP / BMP / GIF / SVG / AVIF / TIFF / ICO / APNG, up to 20 MB each. Images are processed in your own browser and never uploaded.
No image loaded yet
Output settings
Target format
Pick a target format - the result is recomputed as you go.
Only JPEG, WEBP, GIF and AVIF respond to quality: lower means a smaller file and more visible loss.
Leave empty or use 100 to keep the original size; give a width or height to scale proportionally.
Converted result
Converting…Features
- Ten formats, any direction: PNG, JPEG, WEBP, BMP, GIF, SVG, AVIF, TIFF, ICO and APNG convert into each other, and all ten are accepted as input.
- Quality and size under control: set the encoder quality for JPEG, WEBP and AVIF, or the colour count for GIF, and watch the output size move against the original in real time.
- Transparency on your terms: keep the alpha channel when the format allows it, or flatten onto a colour you choose instead of being forced onto white.
- Resize while you are at it: set a width or height to scale proportionally, and ICO output automatically carries 16 to 256 px sizes.
- Entirely local: decoding, scaling, colour quantization and compression all run in your browser. There is no backend to call and nothing is uploaded.
- Preview before you keep it: look at the result and the size comparison first, then download in one click. The interface speaks English, 简体 and 繁體.
How to use
- Click the drop zone to pick an image, drag an image (or a folder of images) anywhere onto the page, or paste with Ctrl+V.
- Choose a target format under Output settings, then drag the quality slider, pick a fill colour for transparent areas and optionally set the output width and height.
- The converted result and a size comparison appear on the right; when it looks right, press Download to save the file locally.
FAQ
- Are my images uploaded to a server?
- No. Every step - decode, scale, colour quantization, compression, packaging - is done by the browser's own Canvas API and the encoders bundled in this page. The page is fully static with no backend and no third-party API, so your image only ever exists in browser memory and leaves no trace in server logs.
- Why did my file get bigger after converting?
- Usually the format direction is backwards. A PNG photo converted to lossless PNG, or to uncompressed BMP, can only get bigger - PNG applies deflate internally while BMP applies no compression at all. Re-encoding an already-small JPEG with a high quality setting inflates it too. The right move is to send photos to JPEG, WEBP or AVIF at quality 70-85, and images with transparency to PNG or WEBP. If you want a smaller file without changing format, the image compression tool on this site does a much better job.
- Where does the transparent background go when I convert to JPEG?
- JPEG has no concept of transparency, so transparent pixels have to land on some concrete colour. Browsers default to white; this page exposes that step as the transparency fill setting. Fill in your page background colour for dark layouts, or red or blue for ID photos and e-commerce cutouts, and you avoid the ugly white or black fringe. BMP and TIFF behave the same way.
- What is the difference between GIF and APNG, and which should I pick?
- GIF is limited to 256 colours, so gradients and photographs band badly and pick up noise, but it has broad compatibility and usually a smaller file. APNG rides on PNG's chunks, keeps full 24-bit colour and per-frame transparency, and looks clearly better - at the cost of a larger file. Here the GIF quality slider controls the quantizer (lower means fewer colours and a smaller file), so try lowering quality first when GIF bands. Choose APNG when animation quality matters more than file size.
- My AVIF will not open, and how do I actually use SVG and ICO?
- AVIF needs a fairly recent browser to decode; messaging apps, mail clients and older Windows builds often cannot display it, so target WEBP or JPEG there. The SVG output here embeds the bitmap in a vector container (the viewBox matches the pixel size), which is the handy part - it scales cleanly with CSS - but it is a wrapper, not a trace: the bitmap gains no new detail, so redraw illustrations in a vector editor. The ICO writes 7 sizes (16, 24, 32, 48, 64, 128, 256 px) into one file, which browsers and Windows pick from automatically; rename it to favicon.ico and drop it in your site root.
About this tool
Image Format Converter is an online image format converter: one upload, any direction between PNG / JPEG / WEBP / BMP / GIF / SVG / AVIF / TIFF / ICO / APNG, with a quality slider, a transparency fill colour and output sizing - and a size comparison plus preview for the result.
PNG, JPEG, WEBP and AVIF are produced by the browser's own encoders; BMP, TIFF, ICO, SVG, APNG and GIF (frequency-based colour quantization + Floyd-Steinberg dithering + LZW compression) are written by encoders bundled in this page, with no third-party library. The page has no backend and no external API, and the interface speaks English / 简体 / 繁體.
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If what you need is a smaller file rather than a different format, use the image compression tool: it palette-quantizes PNG and re-encodes JPEG with mozjpeg, which beats plain format swapping by a wide margin.
Runs in your browser · nothing is uploaded · free · English / 中文