1. Sentence-aware, not character-chopping. X-Split looks for . ! ? first, then word boundaries. The thread reads naturally.
2. No accounts, no data, no API keys. Private by design.
3. URL-aware. Counts URLs at 23 chars matching X's t.co
4. Live re-sync. Edit your original text after splitting, and the sidebar detects the change and prompts re-split.
