> ## Documentation Index
> Fetch the complete documentation index at: https://docs.biom.science/llms.txt
> Use this file to discover all available pages before exploring further.

# File Conversion

> Client-side image decoding and optional format conversion.

# File Conversion

## Client-side decoding (no server required)

Relay decodes the vast majority of scientific image formats directly in the browser using WebAssembly — no BioFormats server, no conversion step, and no round-trip to a backend. This covers **95%+ of scientific image file types** including TIFF, OME-TIFF, CZI, ND2, LIF, DICOM, FITS, and more.

Most web-based scientific viewers require a server-side rendering pipeline (typically BioFormats or similar) to convert proprietary formats before they can be displayed. Relay skips this entirely — files open instantly in the browser.

### Supported client-side formats

| Format              | Notes                                                                       |
| ------------------- | --------------------------------------------------------------------------- |
| **TIFF / OME-TIFF** | Multi-channel, Z-stacks, time-series. Tile-based streaming for large files. |
| **CZI** (Zeiss)     | Full multi-channel support, decoded in-browser via WASM.                    |
| **ND2** (Nikon)     | Full multi-channel support, decoded in-browser via WASM.                    |
| **LIF** (Leica)     | Full multi-channel support, decoded in-browser via WASM.                    |
| **DICOM**           | Medical imaging with window/level presets.                                  |
| **FITS**            | Astronomical images.                                                        |

## Optional export conversion

While viewing is fully client-side, Relay also supports exporting files to open standards when needed (e.g., for sharing or archival):

## Metadata extraction

On upload, Relay automatically extracts metadata from your files:

| Format        | Extracted Fields                                       |
| ------------- | ------------------------------------------------------ |
| TIFF/OME-TIFF | Compression, pages, DPI, OME-XML, channels, pixel size |
| PNG/JPEG/WebP | Width, height, color space, DPI, EXIF data             |
| DICOM         | Format detection, window/level defaults                |
| NWB/HDF5      | Format detection, hierarchical structure               |
| CSV/TSV       | Column count, row count, headers                       |