CaptionRoom vs SmartSub

CaptionRoom is a browser-based video editor with AI captions and a timeline editor. Its editing tools include cuts, picture-in-picture layers, text and image overlays, audio tracks, and colour effects. The free plan supports manual captions in two styles, exports up to 1080p with SRT files, and adds no watermark. Captions can be burned into video, and brand caption presets are available. Pro adds AI captions that transcribe and time words in 99+ languages, an editable transcript, karaoke-style captions, AI Clips, translation, filler-word cleanup, and generated titles, descriptions, and hashtags. Pro exports up to 4K. Free accounts can earn AI credits by watching short ads, and AI jobs use credits. Video files, projects, edits, and exports stay on the user’s device; extracted audio is sent for transcription and, the page says, is not retained afterward. Caption text for Pro translation, cleanup, and title or hashtag tools goes to CaptionRoom’s servers. The editor runs in supported browsers on Windows, Mac, and Linux without installation. Pro is $12 a month billed annually; monthly billing is $20 a month.

SmartSub is an open-source desktop app for transcription, subtitle translation, proofreading, AI dubbing and video subtitle rendering. It runs on Windows, macOS and Linux, and is free with no local usage limits. For local processing, its maker says models process files on the user's computer, so those files do not leave the device. Transcription options include whisper.cpp, faster-whisper, FunASR, Qwen3-ASR and FireRedASR. Translation includes 20 services, including built-in free translation and integrations such as DeepSeek, Gemini and Ollama. The proofreading workspace offers video-synced editing, undo and redo, search and replace, and AI proofreading. SmartSub can generate speech from subtitle lines, align audio to the timeline and clone voices with ZipVoice, Volcengine or ElevenLabs. It can burn subtitles into video or package soft subtitles, preview styles and include dubbed audio. It also downloads videos from links using yt-dlp and lux, supporting more than 1,800 sites. Cloud transcription uploads audio to the configured provider endpoint; the README advises against using it for sensitive content.