Supported formats
The table below lists which formats LITTLEImg can read and write, and how each handles transparency, animation and metadata. Support for some formats depends on your browser and is detected at runtime.
Last checked: 2026-07-25.
| Format | Input | Output | Transparency | Animation | Metadata | Notes |
|---|---|---|---|---|---|---|
| JPEG / JPG | Yes | Yes | No | No | Yes | Best for photographs. Lossy; no transparency. |
| PNG | Yes | Yes | Yes | No | Yes | Lossless. Great for graphics, screenshots and transparency. |
| WebP | Yes | Yes | Yes | First frame only | Yes | Modern format with lossy and lossless modes. Animated WebP is processed as the first frame only. |
| AVIF | Yes | Yes | Yes | No | Yes | Very efficient but slow to encode. Output appears only when your browser supports AVIF encoding. |
| GIF | Yes | No | Yes | First frame only | — | Accepted as input; only the first frame is used. Not offered as an output format. |
| BMP | Yes | No | No | No | — | Accepted as input and converted to a modern format. |
| SVG | Yes | No | Yes | No | — | Sanitised (scripts and external references removed) then rasterised to a bitmap format. |
| HEIC / HEIF | No | No | No | No | Yes | Disabled by default — browser decoding support is inconsistent. Enable only where supported. |
| TIFF | No | No | Yes | No | Yes | Not supported for processing in this build; convert to PNG or JPG first. |
Recommended uses
- Photographs: JPEG or WebP (lossy).
- Graphics, screenshots, transparency: PNG or lossless WebP.
- Maximum web efficiency: WebP, or AVIF where supported.
- Maximum compatibility: JPEG or PNG.