While TikTok and Instagram Reels may seem similar, each platform has unique captioning requirements and best practices. Understanding these differences can significantly improve your engagement rates.
TikTok Caption Best Practices
- Use word-by-word highlighting — This is the signature TikTok caption style that viewers expect.
- Keep text centered — TikTok's UI has elements at the top and bottom; keep captions in the middle third.
- Large, bold fonts — Viewers scroll quickly; make your text impossible to miss.
- High contrast — White text with a shadow/outline for readability on any background.
Instagram Reels Caption Best Practices
- Subtler styling — Reels viewers tend to prefer slightly more polished, less "raw" captions.
- Position above the description — Instagram shows usernames and captions at the bottom; keep subtitles higher.
- Consider your brand aesthetic — Instagram is more brand-conscious; match caption colors to your palette.
Universal Tips for Both Platforms
- Always use portrait (9:16) format subtitles
- Keep sentences short — 5-8 words per line maximum
- Use contrasting colors for readability
- Time your captions precisely to speech (FastCaption does this automatically)
- Test with sound off — if the message is clear, your captions work
How FastCaption Handles Both
FastCaption generates ASS subtitles optimized for both platforms. Choose "Portrait" orientation for 9:16 output with word-by-word highlighting that works perfectly on TikTok and Reels. The styling is automatically positioned to avoid UI elements.