Compress & Convert Images. Instantly.
100% in your browser. Your images are never uploaded anywhere.
Drag & drop images here
Everything happens in your browser: your images are never uploaded anywhere. You can also just paste (Ctrl/Cmd+V) an image or an image URL.
How it works
Convert or compress an image in three simple steps.
Upload your image
Drag and drop a file, click to browse, or paste it straight from your clipboard.
Pick a format and quality
Choose the output format (JPG, PNG, WebP, AVIF, GIF, BMP, or ICO) and adjust the quality slider if you want.
Download the result
Your converted or compressed image is ready instantly: download it, no waiting.
Popular conversions
Or crop, straighten, adjust, remove the background, and resize an image before you convert it.
Which image format should you use?
A quick comparison of JPG, PNG, WebP, AVIF, GIF, BMP, and ICO to help you pick the right one.
| Format | Compression | Transparency | Animation | Best for |
|---|---|---|---|---|
| JPG | Lossy | No | No | Photos and photographs, where a small file size matters more than pixel-perfect detail |
| PNG | Lossless | Yes | No | Logos, screenshots, and graphics that need transparency or sharp, clean edges |
| WebP | Lossy or lossless | Yes | Format supports it | Modern websites: smaller files than JPG or PNG at similar visual quality |
| AVIF | Lossy or lossless | Yes | Format supports it | The best compression available today, ideal for cutting page-load size |
| GIF | Lossless, 256-color palette | Limited (1-bit) | Yes | Short, looping animations and reaction images |
| BMP | Uncompressed | Yes | No | Maximum compatibility with older Windows software, or an uncompressed source file |
| ICO | Lossless (PNG-based) | Yes | No | Website favicons and Windows app icons |
Note: MonsterConvert converts WebP and AVIF as static images. Animation is only preserved when compressing an animated GIF, since that's the only pairing here where both the source and target support motion.
Your Images Never Leave Your Device
Most online image tools upload your files to a server, convert them somewhere else, then send the result back, which means your photos pass through someone else's infrastructure. MonsterConvert works differently: every compression and conversion runs locally in your browser using WebAssembly, built on the same production-grade codecs (mozjpeg, libwebp, libavif) that power Google's Squoosh. There's no upload step, no server-side storage, and no third party ever sees your files.
Frequently asked questions
Yes, MonsterConvert is free to use today. You can convert, compress, and edit images right now without paying anything.
No. MonsterConvert processes every image entirely in your browser using WebAssembly, so your files never leave your device. This is different from most online image converters, which upload your photos to a remote server before returning a result.
You can convert and compress JPG, PNG, WebP, AVIF, GIF, BMP, and ICO, in any direction between them, including animated GIFs. MonsterConvert also supports converting between PDF and images.
Some quality loss is expected with lossy formats like JPG, WebP, and AVIF, but MonsterConvert uses production-grade codecs (mozjpeg, libwebp, libavif) and lets you control the quality level yourself, so you can balance file size against visual quality. Lossless formats like PNG keep every pixel exactly as-is.
Yes. You can drag and drop or select several images at once and process them all in a single batch, each with its own target format and quality setting if you need it.
No. MonsterConvert runs entirely in your web browser, so there's nothing to download or install. Just open the page and start converting or compressing images.
Yes, the Edit tool lets you crop, straighten, rotate, flip, adjust brightness/contrast/saturation, resize, and remove the background from an image, all with a live preview before you download the result.
Yes. MonsterConvert works in any modern browser, including on iOS and Android, since all the processing happens on-device rather than requiring a desktop app.