Image Converter — Free, Fast & Private
Need to convert an image from one format to another? MiniPx handles all major formats in your browser — no upload, no server, no waiting. Whether you need to convert a PNG screenshot to a smaller JPG, turn a WebP image into a universally compatible format, or convert iPhone HEIC photos to something you can actually share, it all happens instantly on your device.
The most common conversions are PNG to JPG (for smaller file sizes), JPG to WebP (for faster websites), and HEIC to JPG (for sharing iPhone photos). MiniPx also handles less common formats like BMP, TIFF, and SVG rasterization — all without installing any software. Windows users with .jfif downloads can convert JFIF to JPG to fix the extension, or JFIF to PNG for a lossless working copy.
Unlike cloud-based converters, MiniPx never touches your files. Your images stay on your device throughout the entire conversion process. This makes it safe for converting sensitive documents, personal photos, and ID images.
Every conversion preserves as much quality as the target format allows. When converting to lossy formats like JPG, you can control the compression level. When converting to lossless formats like PNG, you get pixel-perfect output.
MiniPx supports batch conversion — add multiple images and convert them all at once. Each file is processed independently so you can mix input formats in a single batch.
Format-specific guides: the AVIF converter covers next-gen compression with 30-50% smaller files than JPEG, and the WebP converter hub explains when WebP beats JPEG for web delivery. For JPEG XL (best compression but limited browser support), see the JPEG XL converter. One output stands apart from all of these: PNG to ICO packs several resolutions into a single .ico for favicons and Windows icons — a container, not a picture format.
Converting to WebP and AVIF
If the destination is a website, WebP and AVIF are usually the right targets rather than JPG. Coming from an iPhone, HEIC to WebP skips the pointless detour through JPEG, and HEIC to AVIF is the only route that keeps the 10-bit colour an iPhone actually captures.
Coming from an older format, the savings are dramatic: BMP to WebP cuts around 95% because BMP applies no compression at all, and BMP to AVIF pushes that towards 98%. For GIFs, GIF to WebP and GIF to AVIF escape the 256-colour palette, while GIF to PNG is the lossless option. All three produce a still frame rather than an animation.
For scans and print masters, TIFF to WebP makes archive material web-ready, and TIFF to AVIF is the only target that preserves a scanner’s 10-bit colour depth. Vector artwork rasterises through SVG to WebP or SVG to AVIF for the many platforms that reject SVG uploads.
Between the two modern formats: WebP to AVIF buys another 20-30%, and AVIF to WebP trades that back for broader support in tools and uploaders that still reject AVIF.
Colour depth, and when a conversion costs you
Colour depth is how many bits describe each pixel, and it decides what a format can represent at all. 8-bit indexed — GIF and some PNGs — stores a palette of at most 256 colours and points each pixel at an entry. 24-bit truecolour — JPEG, PNG-24, WebP — gives 8 bits per channel, about 16.7 million colours. Deep colour, 10 or 12 bits per channel, is what HDR and AVIF can carry.
Conversions that reduce depth are the ones that cost you, and they are irreversible. Converting a photograph to an indexed format forces a palette down to 256 entries and introduces dithering — a scattered speckle of two colours faking a third. It reads as a smooth gradient at a glance and as visible noise close up. Going back to truecolour reproduces the speckle faithfully, because by then it is genuinely part of the image.
Conversions that raise depth are safe but gain nothing on their own: a GIF converted to PNG can hold 16.7 million colours and still contains only the 256 the GIF had. The depth ceiling lifts; the colours do not come back.