Upload any video or audio file and get accurate, well-timed captions in minutes. Fine-tune in our built-in editor, then export as SRT, VTT, or burned-in MP4.
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Drop your video or audio file. Fluen auto-detects the language and starts transcribing immediately. Supports MP4, MOV, MKV, AVI, MP3, WAV, and more.
Review captions synced to your media in our built-in editor. Fix any rare errors, adjust timing, and add speaker labels. The editor does the heavy lifting.
Download as SRT, WebVTT, burned-in MP4, or plain text. Customize subtitle styling for burned-in exports. Your captions, your format.
We route your file to the best speech engine for your content type, language, and audio quality.
Captions are split at natural sentence boundaries with proper character-per-line limits for readability.
Detects speaker changes in interviews, podcasts, and multi-person recordings. A dash marks each new speaker turn.
Define how technical terms, brand names, and jargon should appear in your captions. The AI respects your glossary.
Full control over font, color, backing plate, and on-screen positioning. Generate burned-in MP4s with your captions embedded directly into the video — ready to upload anywhere.
Upload multiple files at once. Queue them up and let Fluen process your entire content library in the background.
Boost discoverability and watch time with accurate captions. YouTube rewards accessible content in search and recommendations.
Turn episodes into searchable transcripts and video clips with captions. Repurpose audio content for social media.
Deliver broadcast-quality subtitle files in industry-standard formats. Cut hours from your localization pipeline.
Use AI-generated captions as a high-quality starting point. Your team reviews and refines — faster turnaround, lower cost.
Make courses accessible and compliant. Subtitles improve retention and help non-native speakers follow along.
Caption town halls, training videos, and internal comms. Ensure your message reaches every employee, everywhere.
Fluen can also translate your captions into 50+ languages with production-ready formatting.
Fluen achieves up to 99.2% accuracy by routing your file to the best speech-to-text engine for your content type, language, and audio quality. Our multi-engine approach means you're not locked into a single AI — Fluen picks the one that performs best for your specific file. Combined with our smart segmentation, captions come out well-punctuated, properly capitalized, and split at natural sentence boundaries.
Fluen supports all major video formats including MP4, MOV, MKV, and AVI, as well as audio formats like MP3, WAV, M4A, and FLAC. If you already have subtitle files, you can import SRT files directly during the caption review step.
You can export your captions as SRT (the most widely used subtitle format), WebVTT (for web and HTML5 video), burned-in MP4 (with customizable subtitle styling baked into the video), or plain text transcripts. Each format is optimized for its intended use case.
Most files are processed in minutes. A 60-minute video typically takes 3–5 minutes to transcribe. Processing time depends on file length, audio quality, and the AI engine selected. You'll be notified as soon as your captions are ready for review.
Yes. In the built-in editor, you can adjust timing, edit text, and add speaker labels. For burned-in MP4 exports, you can customize font, size, color, position, and background opacity. You can also set workspace-level subtitle specs like max characters per line and max lines per cue.
Yes. Fluen includes speaker diarization that detects when a new person starts speaking. When a speaker change is detected, a dash is prepended to the beginning of the cue to visually indicate the transition. This is especially useful for interviews, podcasts, and panel discussions where distinguishing between speakers matters.
Absolutely. Once you've generated and reviewed your captions, you can translate them into 50+ languages with Fluen's AI translation engine. Translations are context-aware and automatically re-segmented for each target language. Learn more about subtitle translation →
Yes. You can sign up and process your first 3 files completely free — no credit card required. This gives you access to the AI captioning engines and the built-in editor so you can evaluate the quality before committing to a plan. See pricing →
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