A 12MB PNG for an Instagram post
Instagram’s publishing API accepts JPEG images up to 8MB; a 12MB PNG would need to be compressed and converted before it can be scheduled.
Instagram Reel video specs & media checker
Look up Instagram Reel video specs — plus accepted formats, file-size ceilings and video duration for every major platform — the same specs SkedCast's own composer validates before a post can be scheduled.
Image specs
| Platform | Formats | Max size |
|---|---|---|
| X (Twitter) | JPEG, PNG, WEBP, GIF | 5MB |
| JPEG, PNG, GIF | 5MB | |
| JPEG | 8MB | |
| Facebook Pages | JPEG, PNG | 10MB |
| TikTok | JPEG, WEBP, PNG | — |
| YouTube | Not supported | |
| Threads | JPEG, PNG | 8MB |
| JPEG, PNG | 20MB | |
| Bluesky | JPEG, PNG, WEBP | 1MB |
| Telegram | JPEG, PNG | 10MB |
Video specs
| Platform | Formats | Max size | Max length |
|---|---|---|---|
| X (Twitter) | MP4, MOV | 512MB | 2m20s |
| MP4, MOV, WEBM | 5GB | 30m | |
| MP4, MOV | 1GB | 15m | |
| Facebook Pages | MP4, MOV | 10GB | 4h |
| TikTok | MP4, MOV, WEBM | 4GB | 10m |
| YouTube | MP4, MOV, WEBM, AVI | 256GB | 12h |
| Threads | MP4, MOV | 1GB | 5m |
| MP4, MOV, M4V | 2GB | 15m | |
| Bluesky | MP4, MPEG, WEBM, MOV | 300MB | 3m |
| Telegram | MP4 | 50MB | 5m |
GIF specs
| Platform | Formats | Max size |
|---|---|---|
| X (Twitter) | GIF | 15MB |
| GIF | 5MB | |
| Not supported | ||
| Facebook Pages | GIF | 30MB |
| TikTok | Not supported | |
| YouTube | Not supported | |
| Threads | GIF | 8MB |
| GIF | 20MB | |
| Bluesky | GIF | 1MB |
| Telegram | GIF, MP4 | 50MB |
How to check Instagram Reel video specs and other platforms
- Find your platform and media kind. Look up the row for the exact platform and whether you are attaching an image, a video or a GIF, since each has its own spec.
- Check the format first. Confirm your file is in an accepted format for that platform and media kind — an unsupported format fails before size or duration is even checked.
- Check the file size against the ceiling. Compress or re-export before scheduling if your file exceeds that platform’s maximum, since most publishing APIs reject an oversized file outright.
- Check duration for video. Trim any video that exceeds the platform’s maximum duration, and remember Reels/Shorts formats often have a separate, shorter limit than a standard feed video.
- Treat these as API limits, not always in-app limits. A platform’s own app sometimes accepts a slightly different format or size than its publishing API — these specs describe what a scheduler can actually publish.
Worked examples
A 600MB video for X
X’s video upload allows files up to 512MB; a 600MB export needs re-compressing to fit, independent of whether its 140-second duration is already within limits.
A WebM video for TikTok
TikTok accepts MP4, MOV and WebM video files up to 4,096MB and 600 seconds, so a WebM export is fine as long as it clears the size and duration ceilings.
Media spec FAQ
- What image formats does each platform accept?
- Most platforms accept JPEG and PNG; Instagram’s publishing API is JPEG-only (PNG and WebP get converted), and TikTok’s photo posts additionally accept WebP.
- What is the largest video file size a platform will accept?
- It varies widely — X caps video at 512MB, TikTok at 4,096MB, Facebook feed video at 10,240MB, and YouTube at 262,144MB, reflecting how differently each platform is built for video.
- Do GIFs work the same as videos?
- No — most platforms that accept GIFs treat them as a static image rather than an animated video, including Facebook, Threads, Bluesky and Pinterest, so an animated GIF often posts as a single still frame.
- Why would a file fail even though it looks fine in the app?
- Because a platform’s own app and its publishing API do not always share identical limits — the API a scheduler uses can be stricter, or occasionally more permissive, than what you can upload by hand in the app.
- Does every platform support video?
- Yes, all 10 major platforms in this table support video in some form, but the duration and file-size ceilings differ enormously — from X’s 140 seconds to YouTube’s 12-hour maximum.
- What happens if a file exceeds the spec?
- Most publishing APIs reject an out-of-spec file outright with an error, rather than resizing, trimming or compressing it automatically — the file has to be fixed before it will schedule.
- Are these specs the same everywhere the platform is used?
- These reflect each platform’s own publishing API as documented today; a platform can and does change its specs, so a rejected file is also worth checking against that platform’s current developer documentation.
- Are Instagram Reel video specs the same as the regular Instagram video row above?
- Not necessarily — the Instagram video row above is the general publishing-API video limit this checker validates against, and Reels have historically carried their own, often shorter, duration and format rules than a standard feed video. Treat the row above as your file-size and format ceiling, and confirm the current Reels-specific duration cap in Instagram’s own app or developer docs.
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