Image format problems tend to appear at inconvenient moments: a HEIC from an iPhone that a client's system won't accept, a PNG that needs to be a JPG for an upload form, a TIFF from a print project that's too large to email, a WebP that won't open in older software. The formats themselves aren't the problem — each exists for a reason — but mismatches between what you have and what a platform or recipient expects are common enough to need a fast solution.
Portimg's image converter handles conversion between the formats you're most likely to encounter, in the browser, without an account.
What each format is actually for
Understanding why formats exist makes it easier to choose the right output rather than just converting to whatever seems familiar.
JPG is the default for photographs and image-heavy content. It uses lossy compression that reduces file size by discarding data the human eye is unlikely to notice. The tradeoff is that re-saving a JPG repeatedly degrades quality incrementally, and it doesn't support transparency. For photographs going to the web or shared by email, it remains the most universally compatible option.
PNG is lossless — every pixel is preserved exactly — and supports transparency, making it the right choice for logos, icons, screenshots, and any image where you need a transparent background or crisp edges on text and graphics. The tradeoff is larger file sizes than JPG for photographic content.
WebP produces smaller files than JPG at comparable visual quality, or better quality at the same file size. It also supports transparency like PNG. It's the best format for web use and is now supported by all major browsers. If you're preparing images for a website, converting to WebP before upload is one of the more impactful quick improvements you can make to page load times.
AVIF achieves even better compression than WebP and is the most efficient format currently in widespread use. Browser support is broad but not universal across older software, so it's best suited for web contexts where you can verify support, rather than files you're sending to people whose software you don't know.
HEIC is Apple's default photo format on iPhones and iPads. It produces smaller files than JPG at equivalent quality, but support outside Apple's ecosystem is inconsistent — many Windows applications, web platforms, and older software won't open it. Converting HEIC to JPG or PNG is the standard fix when a file needs to work outside an Apple device.
TIFF and BMP are lossless formats used in professional print, archival, and design workflows where maximum quality and no compression artefacts are required. They produce large files and aren't suited for web or email, but are the right choice when image data needs to be preserved exactly.
SVG is a vector format — it stores images as mathematical descriptions rather than pixels, which means it scales to any size without quality loss. It's the standard for logos, icons, and illustrations used at multiple sizes. Converting a raster image (JPG, PNG) to SVG doesn't make it a true vector; that requires either recreating the image in vector software or using a dedicated raster-to-vector conversion tool.
Converting with Portimg
Go to portimg.com/raster-to-raster-converter, upload your image or images, select your output format, and download the converted files. Multiple files are packaged as a ZIP. No account required, and files are deleted after processing.
The supported conversions cover the most common format mismatches: PNG to JPG, JPG to WebP or AVIF, HEIC to JPG or PNG, TIFF or BMP to JPG or WebP, GIF to PNG or JPG, and SVG to PNG or JPG. For the full current list, the tool shows available output options once you upload a file in a given format.
A few things worth knowing
Converting from a lossless format (PNG, TIFF) to a lossy one (JPG, WebP) involves a quality decision. The default settings are reasonable for most uses, but if you're converting professional photography or print assets, check the output before discarding originals — the compression level affects fine detail in ways that may or may not matter for your use case.
Converting from JPG to PNG doesn't make the image lossless. The quality loss from the original JPG compression has already happened; PNG just stores the current pixel values without further compression. The file gets larger without any quality improvement. This conversion only makes sense when you need a PNG specifically — for transparency support, or for a platform that requires it.
For batch conversion of large numbers of files on a recurring basis, a desktop tool like XnConvert or a command-line tool like ImageMagick will be more efficient than a browser tool. Portimg is best suited for on-demand conversions where you have a specific file or batch to deal with right now.