cometpost

Caption and media limits checker

Check a caption and your media against the limits cometpost enforces when you schedule a post. Your text and files stay in your browser: nothing is uploaded.

Platforms

Limits are only shown for platforms cometpost can publish to today. YouTube is in limited release: until Google completes its audit, videos uploaded through cometpost stay private.

Characters are counted as Unicode characters, so an emoji counts as one. A platform's own count can differ, for example for links.

Only the file name, type, size and (for images) the pixel size are read, in your browser. The files are not uploaded.

    Results

    This is a check, not a guarantee. It tests your post against the limits cometpost applies before it schedules a post. A platform can still refuse a post that passes, for reasons this tool cannot see: the platform may change its rules, the account may not be eligible, or the content may break the platform's policies. cometpost refuses a post over these limits rather than trimming it for you.

    The limits

    PlatformCaptionMedia itemsFile typesLargest fileImage shape (width / height)
    Threads500 characters0 to 1JPEG, PNG, MP48 MiBAny
    Instagram2200 characters1 to 10 (a post needs media)JPEG8 MiB0.8 to 1.91 (4:5 to 1.91:1)
    YouTube (limited release)5000 characters (the description), plus a required title of up to 100 charactersExactly 1 videoMP4, MOV, AVI, WMV, FLV, 3GP, WebM, MPEG256 GiBNot checked
    TikTokComing soon. No limits are shown until it is available.
    Facebook PagesIn review by the platform. No limits are shown until it is available.
    XComing soon. No limits are shown until it is available.

    Snapshot of cometpost's own platform data, taken from the product code at commit b337c74. Video length, frame rate and codec are not checked here. For video, cometpost also reads the file when you schedule it.