# Platform Specifications Quick Reference

## Video Specs

| Platform | Orientation | Resolution | Codec | Bitrate | FPS | Audio | Duration |
|----------|------------|------------|-------|---------|-----|-------|----------|
| B站 | Horizontal 16:9 | 3840×2160 | H.264 | 16Mbps | 30 | AAC 192k | 3-12min |
| YouTube | Horizontal 16:9 | 3840×2160 | H.264 | 16Mbps | 30 | AAC 192k | 3-12min |
| 小红书 | Vertical 9:16 | 2160×3840 | H.264 | 16Mbps | 30 | AAC 192k | 30-120s |
| 抖音 | Vertical 9:16 ONLY | 2160×3840 | H.264 | 16Mbps | 30 | AAC 192k | 30-120s |
| 视频号 | Vertical 9:16 ONLY | 2160×3840 | H.264 | 16Mbps | 30 | AAC 192k | 30-120s |

## Thumbnail Specs

| Platform | Sizes Required | Dimensions |
|----------|---------------|------------|
| B站 | 16:9 + 4:3 | 1920×1080 + 1200×900 |
| YouTube | 16:9 + 4:3 | 1920×1080 + 1200×900 |
| 小红书 | 16:9 + 3:4 | 1920×1080 + 1080×1440 |
| 抖音 | 9:16 | 1080×1920 |
| 视频号 | 9:16 | 1080×1920 |

## Title Rules

| Platform | Max Chars | Style |
|----------|----------|-------|
| B站 | 80 | Number + topic + hook formula |
| YouTube | 70 | SEO-optimized |
| 小红书 | **20** | Punchy + emoji |
| 抖音 | 55 | Short + casual |
| 视频号 | 55 | Knowledge-sharing |

## Tag/Hashtag Format

| Platform | Count | Format | Example |
|----------|-------|--------|---------|
| B站 | 10 | Plain words | AI, 人工智能, AIDLC |
| YouTube | 15 | Plain + #hashtags | #AI #AgentArchitecture |
| 小红书 | 5-10 | `#tag#` (DOUBLE hash) | #AI实践# #技术分享# |
| 抖音 | 3-8 | `#tag` (SINGLE hash) | #AI #人工智能 |
| 视频号 | 3-8 | `#tag` (SINGLE hash) | #AI #技术管理 |

## Description Rules

| Platform | Length | Style |
|----------|--------|-------|
| B站 | 100-200 chars | Knowledge-sharing, professional |
| YouTube | 100-500 chars | Keyword-rich, chapters included |
| 小红书 | 200-500 chars | 种草 style, emoji, line breaks |
| 抖音 | 100-200 chars | Casual, conversational, emoji |
| 视频号 | 100-300 chars | Professional, forwarding-friendly |

## Chapter Support

| Platform | Supported | Format | Notes |
|----------|-----------|--------|-------|
| B站 | Yes | `MM:SS` | Min 5s gap between chapters |
| YouTube | Yes | `M:SS` | First chapter MUST be at `0:00` |
| 小红书 | No | — | — |
| 抖音 | No | — | — |
| 视频号 | No | — | — |

## CTA Rules

| Platform | Type | Text | Animation |
|----------|------|------|-----------|
| B站 | Animation | 一键三连 (点赞投币收藏) | Pre-made MP4 (light/dark) |
| YouTube | Text/Animation | Like, Subscribe & Share | Optional |
| 小红书 | Text Animation | 点赞收藏加关注 | Text overlay |
| 抖音 | Text ONLY | 点赞关注 | NO animation |
| 视频号 | Text ONLY | 点赞关注，转发给朋友 | NO animation |
