video-spec-sheet

name: video-spec-sheet title: "Video Spec Sheet — Platform Specs and Safe Zones" description: "Canonical reference for platform-by-platform video output specs: aspect ratio, length cap, codec, bitrate, frame rate, color, caption style and safe-zone bands. Use when picking output settings, validating an export, or spec-checking before publishing. Covers TikTok, Reels, Shorts, IG/FB feed, Stories, X, LinkedIn — all four format families: short-form vertical, square/feed, long-form 16:9, story 9:16." license: Apache-2.0 compatibility: "Stack-agnostic." domains: video rules: - session(video) - session(adcraft) - content(reels) - content(shorts) - content(tiktok) - content(instagram stories) - content(aspect ratio) - match(\bsafe\s+zone\b) - match(\b(video\s+)?codec\b) - match(\b(video\s+)?bitrate\b) - match(\bplatform\s+specs?\b) - match(\b(9:16|16:9|1:1|4:5)\b) - semantic(what dimensions should I export this video at) - semantic(safe export settings for TikTok or Reels) - semantic(what are the platform specs for short-form video) - semantic(which codec and bitrate should I use for vertical video) - semantic(why does my video get cropped on Instagram)

Overview

Each social platform has its own combination of aspect ratio, max duration, codec, bitrate, frame rate, and caption / UI safe zones. Getting any of these wrong on the export means the platform will either reject, re-encode (quality drop), or crop your creative. This skill encodes the current 2026 specs as a single-source-of-truth table the agent can extract from per brief.

Instructions

Core Rules

• Always pick the platform spec before generating frames — generation must match the export aspect ratio (don't generate 16:9 then crop to 9:16 unless intentional).
• Burn captions on top of the base render, not as a sidecar — sound-off viewing is the default.
• Respect the safe zone — keep all critical text and faces away from where the platform's UI sits (top, bottom, right side for TikTok).
• Final encode in H.264 / yuv420p, even if the source is HEVC / 10-bit. Universal compatibility beats marginal quality.
• Audio: AAC stereo, 128 kbps minimum, 48 kHz sample rate. Mono audio reads as low-quality on most feeds.
• Loudness: -14 LUFS integrated (TikTok / IG / YT now normalize to roughly this — overshooting means platform compression hits you).

Platform Spec Table

Safe Zones (don't put critical content here)

(All measured at 1080×1920 or 1920×1080. Scale with output resolution.)

Captions / On-Screen Text Rules

• Center caption block, never bottom-aligned (bottom is platform UI).
• For 9:16: caption block sits roughly in the upper-center third (between Y=600 and Y=1200 of 1080×1920) — avoids both header and CTA bar.
• Font: bold sans (Inter Bold, Helvetica Black, SF Pro Display Bold, Montserrat Black). 80–110 pt for headline hooks at 1080×1920.
• Stroke + drop shadow: 2 px stroke, 1 px shadow, opacity 0.6 — preserves readability over any background.
• One sentence per card max. Two-sentence cards get skipped.
• Word-by-word reveal in time with VO outperforms full-sentence flat captions on TikTok / Reels.

Output Presets (ffmpeg) — copy-paste ready

# 9:16 — TikTok / Reels / Shorts / Stories
-vf "scale=1080:1920:force_original_aspect_ratio=decrease,pad=1080:1920:(ow-iw)/2:(oh-ih)/2:color=black,fps=30" \
  -c:v libx264 -profile:v high -level 4.0 -crf 21 -preset slow -pix_fmt yuv420p \
  -c:a aac -b:a 128k -ar 48000 -ac 2 \
  -movflags +faststart

# 1:1 — IG / FB feed
-vf "scale=1080:1080:force_original_aspect_ratio=decrease,pad=1080:1080:(ow-iw)/2:(oh-ih)/2:color=black,fps=30" \
  -c:v libx264 -profile:v high -crf 21 -preset slow -pix_fmt yuv420p \
  -c:a aac -b:a 128k -ar 48000 -ac 2 -movflags +faststart

# 16:9 — YouTube long-form / LinkedIn
-vf "scale=1920:1080:force_original_aspect_ratio=decrease,pad=1920:1080:(ow-iw)/2:(oh-ih)/2:color=black,fps=30" \
  -c:v libx264 -profile:v high -level 4.2 -crf 19 -preset slow -pix_fmt yuv420p \
  -c:a aac -b:a 192k -ar 48000 -ac 2 -movflags +faststart

Workflow

1. Identify primary platform for the brief (TikTok / Reels / Shorts / etc.).
2. Pick aspect, length cap, fps from the table.
3. Mark safe zones when storyboarding — keep face, hook text, CTA inside the center region.
4. At export, use the matching ffmpeg preset above.
5. If publishing to multiple platforms, render the master in the largest aspect (e.g. 9:16 1080×1920 30fps) and downconvert to others — never upscale.

Decision Guide

Examples

Example 1: TikTok ad export

Source: 4K 16:9 24fps generated at Veo. Target: TikTok ad.

ffmpeg -i source.mp4 \
  -vf "scale=1080:1920:force_original_aspect_ratio=decrease,pad=1080:1920:(ow-iw)/2:(oh-ih)/2:color=black,fps=30" \
  -c:v libx264 -profile:v high -level 4.0 -crf 21 -preset slow -pix_fmt yuv420p \
  -c:a aac -b:a 128k -ar 48000 -ac 2 \
  -movflags +faststart \
  tiktok-ad-9x16.mp4

Example 2: Cross-platform render plan

Brief: One ad, ship to TikTok + IG Reels + IG feed + YT Shorts + YT long-form trailer.

References

• TikTok video specs
• Instagram Reels specs
• YouTube Shorts specs
• Meta Ads guidelines