Every image is stored in a container format, and the choice matters more than most people realize. It affects file size, image quality, transparency, animation, and how much metadata travels with the file. MetaLens detects the true format from a file's contents rather than its extension, so a renamed file is still identified correctly. Here is what distinguishes each of the common formats.
JPEG
The workhorse of digital photography. JPEG uses lossy compression: it discards detail the eye is unlikely to miss, producing small files at the cost of some quality that drops further each time you re-save. It has no transparency, but it is universally supported and carries full EXIF, IPTC and XMP metadata — which is why most geotagged camera photos are JPEGs. Best for photographs where small size matters.
PNG
A lossless format that preserves every pixel and supports full transparency (an alpha channel). That makes it ideal for logos, screenshots, diagrams and graphics with sharp edges, but files are much larger than JPEG for photographic content. PNG can hold some textual metadata, but cameras rarely produce PNGs, so a PNG often shows little or no EXIF — which is why screenshots typically report no embedded metadata.
GIF
An old format limited to 256 colors, best known for simple animations. It supports basic transparency but is a poor choice for photos due to its restricted palette. For animation, modern formats like WebP and AVIF are smaller and far higher quality.
WebP
Google's modern format offering both lossy and lossless compression, transparency, and animation — typically 25–35% smaller than an equivalent JPEG or PNG. It is now widely supported in browsers and is a strong default for web images. It can store EXIF and XMP metadata, though some tools handle it inconsistently.
HEIC / HEIF
The format modern iPhones use by default. HEIC delivers excellent quality at roughly half the size of JPEG and supports advanced features like depth maps and live photos. The trade-off is compatibility: not every app or website accepts HEIC, which is why phones often convert to JPEG when you share. HEIC carries rich EXIF and GPS data just like JPEG.
TIFF
A high-quality, typically lossless format favored in professional photography, printing and archiving. Files are large, but TIFF preserves maximum detail and carries extensive EXIF, IPTC and XMP metadata. It is a storage and editing format, not a format you would put on a web page.
AVIF
One of the newest formats, based on the AV1 video codec. AVIF offers superb compression — often noticeably smaller than WebP at similar quality — with transparency and wide color support. Browser support has grown quickly. Expect to see it more often as the web moves toward it.
BMP and ICO
BMP is an old, uncompressed Windows format that produces very large files and carries almost no metadata. ICO is used for icons and favicons, storing small images at multiple sizes. Both are niche today.
Quick comparison
- Photographs for the web: WebP or AVIF, with JPEG as the safe fallback.
- Graphics, logos, screenshots: PNG (or WebP lossless).
- Editing and archiving: TIFF or the camera's raw format.
- iPhone default: HEIC, converted to JPEG when shared for compatibility.
How format affects your privacy
Because formats differ in what metadata they carry — and because converting between them can add or drop fields — the only reliable way to know what a specific file contains is to inspect it. Upload any image to MetaLens to see its true format and every piece of metadata it holds, then decide whether to strip it before sharing.