SoCaptions

SoCaptions is a web app for adding captions to short-form video. Upload a clip, and Whisper-based transcription produces word-level timing, so captions highlight in sync with speech. Pick a viral-style preset (karaoke, bold outline, box, cinematic, minimal), adjust font, size, position and animation, and edit any word on a timeline. Export a burned-in MP4 ready for TikTok, Instagram Reels, YouTube Shorts or LinkedIn — no watermark on Pro. It also includes free browser-only subtitle tools: SRT/VTT/ASS converters, timing shifter, frame-rate converter, reading-speed (CPS) checker and a YouTube transcript extractor. A public REST API lets scripts and AI agents caption a video with one call. 5 minutes free without a card; Pro is $3/month for 100 minutes.