netstandard1.2, net40, and net8. Zero dependencies on targets ≥ net46. Get your MIME type or extension and be done with it fast. The mapping is zero-config by default and sourced from authoritative sources, such as IANA and MimeType. About 2,000 extensions and MIME types are mapped.
➡️ Try it online: WASM demo
Install the package:
dotnet add package MimeTypeCoreGet MIME type from an extension, or vice versa:
using MimeTypeCore;
MimeTypeMap.TryGetMimeType(".png", out string mimeTypePng); // image/png
MimeTypeMap.TryGetExtension("image/png", out string extension); // .png⭐ That's it! Please consider starring this repository if you find it helpful.
Sometimes, one extension can have multiple MIME types associated. For example, .ts might be text/typescript, or video/mpeg (ts stands for Transport Stream in this case). To resolve the collision, provide Stream to the file, so the header can be sampled for a known sequence of magic bytes:
using FileStream streamVideo = File.Open("files/video.ts", FileMode.Open);
using FileStream streamTypescript = File.Open("files/typescript.ts", FileMode.Open);
MimeTypeMap.TryGetMimeType(streamVideo, out string mimeTypeVideo); // video/mpeg
MimeTypeMap.TryGetMimeType(streamTypescript, out string mimeTypeTypescript); // text/typescriptWhen dealing with user-provided files, whether from Blazor or MVC, your input is likely to be IBrowserFile or IFormFile. These streams don't support synchronous reading, use MimeTypeMap.TryGetMimeTypeAsync:
IBrowserFile file; // for example from InputFileChangeEventArgs
try
{
// 500 MB, use reasonable limits out there
await using Stream stream = file.OpenReadStream(512_000_000);
// null if not recognized, your MIME type otherwise
string? mimeType = await MimeTypeMap.TryGetMimeTypeAsync(args.File.Name, stream);
}
catch (Exception e) // the file size is probably over the OpenReadStream limit
{
}If you need to register custom MIME/file extension pairs, use MimeTypeMap.AddMimeTypes:
MimeTypeMap.AddMimeTypes([
new KeyValuePair<string, string>(".js", "text/javascript")
]);To contribute, check the mapping file for the hardcoded mappings, and add new entries. Please follow the code style and alphabetical ordering; the included utilities Inserter and Formatter will help with that. Magic headers can be contributed to this file. If you are touching anything beyond that, provide relevant test cases. Thank you.
This library is licensed under the MIT license. 💜