File Extension Lookup
Look up file extensions, MIME types, and software compatibility.
Base64 File Encoder / Decoder
100% Client-Side. Files never upload to any remote server.
About File Extension Lookup
The Comprehensive File Extension & MIME Type Reference Database provides instant lookup for 2,000+ file extensions, detailing full format names, associated software applications, MIME media types, and developer documentation.
How to Use File Extension Lookup
Step 1
Type any file extension (e.g. `csv`, `tar`, `woff2`) or MIME type into the search bar.
Step 2
Inspect format details, MIME type, description, and compatible applications.
Step 3
Copy the official MIME type for server configuration.
Practical Use Cases for File Extension Lookup
Identifying Unknown File Extensions
Look up rare, obscure, or proprietary file extensions (e.g. `.crx`, `.wasm`, `.p7b`, `.vtt`) to discover what software opens them.
Configuring Web Server MIME Types
Find the official IANA MIME content type for any file extension to configure Nginx, Apache, or S3 bucket content headers.
Input & Output Examples
Looking up `.webp` Extension
Query: "webp"
Name: WebP Image Format | MIME: image/webp | Category: Raster Image | Developer: Google | Supported By: Chrome, Safari, Photoshop, GIMP
Key Features & Performance
- ✓Instant real-time search across 2,000+ file extensions and MIME content types.
- ✓Categorized filters: Developer/Code, Audio, Video, Image, Document, Archive, System, Database.
- ✓Includes default opening applications across macOS, Windows, and Linux.
- ✓100% Client-Side lookup.
- ✓1-Click Copy MIME type and config snippet.
Key Terminology & Definitions
File Extension
The suffix at the end of a filename (following the period) that indicates the encoding format and associated application.
IANA Media Type Registry
The official Internet Assigned Numbers Authority database of standardized MIME content types used across HTTP and email.