Video and Image Formats Accepted by Mastodon

File formats, sizes, and resolutions for attachments on Mastodon Source: https://github.com/mastodon/mastodon/blob/main/app/models/media_attachment.rb#L42 Format File Size Limit Resolution Extension MIME Type Image 10MB 1920x1080px .jpg, .jpeg, .png, .gif, .webp, .heic, .heif, .avif image/jpeg, image/png, image/gif, image/heic, image/heif, image/webp, image/avif Gifv         Video 40MB 1920x1200px .webm, .mp4, .m4v, .mov video/webm, video/mp4, video/quicktime, video/ogg Audio     .ogg, .oga, .mp3, .wav, .flac, .opus, .aac, .m4a, .3gp, .wma audio/wave, audio/wav, audio/x-wav, audio/x-pn-wave, audio/vnd.wave, audio/ogg, audio/vorbis, audio/mpeg, audio/mp3, audio/webm, audio/flac, audio/aac, audio/m4a, audio/x-m4a, audio/mp4, audio/3gpp, video/x-ms-asf