Checksub vs SmartSub

Checksub provides AI-powered subtitles, dubbing, and voice-over for videos through web, API, and extension platforms. It can create subtitles automatically or synchronize subtitles from a script, and it offers subtitle translation in 200 languages. Its dubbing replaces the original voice while keeping the audio background; Checksub also says users can substitute a cloned voice in 30 languages. The online editor lets users revise and regenerate sentences after subtitle or dubbing generation. Subtitles can be burned into exported videos with animated styles, including karaoke animation. Translated-video publishing to YouTube is supported, and the Starter plan connects one channel. Listed integrations include YouTube, Twitch, Google Drive, Adobe Premiere Pro, DaVinci Resolve, and Final Cut Pro. Credit use varies by task: one credit minute per video minute for subtitles, three for dubbing, and five for lip-sync. The service has a free plan and free trial. Checksub was founded in 2017 and is headquartered in France.

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.