How does the video specs checker work?
- Pick or drop a video. Your browser opens it from your disk with a temporary local link. Nothing is sent to a server.
- It reads the metadata. Length, width and height come from the video's header, the same data a player reads before it starts. File size and type come from the file itself.
- It checks each limit. Every value is compared with the numbers each platform publishes on its own help pages, checked November 4, 2026. A fail says what's wrong and by how much ("too long: 16:20 vs 15:00 max"), and each platform it fails gets a recommended export.
Results come in five kinds. Pass and Fail are what they sound like. Warning means the file is inside the hard limit but something will cost you: a reel over 3 minutes, a YouTube video over 15 minutes on an unverified account, a format that isn't on the platform's list. Not published means the platform gives no number to check. Couldn't read means your browser couldn't decode that part of the file.
A few things a browser can't measure: frame rate, codec and exact bit rate. The checker shows each platform's frame-rate rule beside its result and estimates bit rate as file size ÷ length. File-size limits written as "5 GB" don't say whether a GB is 1,000 or 1,024 MB, so a file between the two readings gets a warning, not a pass.
What does each platform accept?
| Platform | Length | File size | Aspect ratio | Resolution | Specs |
|---|---|---|---|---|---|
| LinkedIn (member posts) | 3 s (2 s in app) to 15 min | 75 KB to 5 GB | 1:2.4 to 2.4:1 | 256×144 to 4096×2304 | Full specs |
| LinkedIn (Company Pages) | 3 s to 10 min | 75 KB to 5 GB | 1:2.4 to 2.4:1 | 256×144 to 4096×2304 | Full specs |
| X (free account) | Up to 2:20 (140 s) | Up to 512 MB | 1:2.39 to 2.39:1 | 32×32 to 1920×1200 (1200×1900 vertical), web | Full specs |
| X (Premium) | Under 4 h (web, iOS); 10 min on Android | Up to 16 GB | 1:2.39 to 2.39:1 | Up to 1920×1200 (web); 720p if over 2 h | Full specs |
| Instagram Reels | Up to 20 min (3 min to be recommended) | Not published | 9:16 to 1.91:1 | At least 720 px | Full specs |
| YouTube | 15 min until verified; up to 12 h | Up to 256 GB | 16:9 standard; vertical and square accepted | Not published | Full specs |
| YouTube Shorts | Up to 3 min | Not published | Square or vertical | Max 1080p | Full specs |
| Facebook (reels) | Any length | Not published | Any | Not published | Source |
| Threads (API docs) | Up to 5 min | Up to 1 GB | 0.01:1 to 10:1 (9:16 recommended) | Max width 1920 px | Source |
| Bluesky | Up to 3 min | Up to 300 MB | Not published | Not published | Source |
| TikTok | Not verified: TikTok's support pages couldn't be opened, so the checker doesn't test TikTok. | – | |||
From each platform's own help pages (Threads: Meta's Threads API docs; Bluesky: its official announcements), checked November 4, 2026. "Not published" means the current pages give no number. Formats, frame rates and the reasoning behind each limit are on the full specs pages: LinkedIn, X, Instagram Reels, YouTube, YouTube Shorts, or all of them on social media video sizes.
Is my video too long for Instagram or LinkedIn?
Instagram: reels can be up to 20 minutes, but Instagram says reels over 3 minutes won't be recommended to new audiences. If reach matters, 3:00 is the real limit. LinkedIn: 15 minutes from a personal profile, 10 minutes from a Company or Career Page, and at least 3 seconds. The often-repeated "10 minutes on mobile" isn't on LinkedIn's own help pages.
The tighter limits are elsewhere. A free X account takes 2:20, YouTube Shorts and Bluesky 3 minutes, Threads 5 minutes. A typical launch video is well inside all of them: the median in our study of 150 Product Hunt launches was 78 seconds.
How do I check a video's resolution online?
Drop it into the checker above: it shows the width, height, aspect ratio and length without uploading anything. For details a browser can't read (frame rate and codec), use one of these:
- Mac: select the file in Finder and press Cmd-I; "More Info" shows dimensions and duration. QuickTime Player's Movie Inspector (Window menu) adds format, frame rate and data rate.
- Windows: right-click the file, choose Properties, then Details: frame width, height, frame rate and bit rate are under Video.
- Command line:
ffprobe -v error -select_streams v:0 -show_entries stream=codec_name,width,height,r_frame_rate:format=duration,size,bit_rate -of default=nw=1 video.mp4
To turn a width and height into a ratio, or find the size for a ratio, use the aspect ratio calculator.
Why can't the checker read my video?
A browser can only report the length and resolution of video it knows how to decode. Chrome and Firefox often can't decode HEVC (H.265) or ProRes, which is what many iPhone recordings and editing exports are, and some MKV, AVI and WMV files fail the same way. When that happens, the checker says so and still tests file size and type, which catches the most common rejections.
To check the rest, open this page in Safari (it decodes HEVC on a Mac), or re-export as MP4 with H.264. That's on every published format list here, and it's our default for X and Instagram, which don't publish one.
Is my video uploaded anywhere?
No. The file is read by your browser on your device. The page sends no part of the video, its name or its details to us or anyone else; the only thing it records is a cookieless page view. You can check unreleased launch videos, and very large files are fine because nothing is transferred.