The ideal speed is 12–21 characters per second (CPS).
Effective subtitles follow a "gold standard" of brevity to ensure viewers can read the text without missing the action on screen. To put together a high-quality post with English subtitles, follow these technical limits and best practices: 📏 Essential Subtitle Limits Limit subtitles English
Aim for 32–42 characters . Exceeding 47 characters may cause text to go off-screen or become unreadable. Lines per subtitle: Keep it to 1–2 lines max . The ideal speed is 12–21 characters per second (CPS)