Video Caption Generator — AI Captions in 99 Languages

Three steps. (1) Upload your video (MP4, MOV, MKV, WebM up to 5 GB) or paste a YouTube URL. (2) VexaScribe transcribes the audio with Whisper Large-v3 in 5-15 minutes at 90-95% accuracy on clean audio, adds speaker labels automatically, and generates timecoded captions. (3) Export as SRT for YouTube/Premiere/DaVinci/CapCut import, VTT for HTML5 web, or download the video with captions burned in. 30 minutes of video are free at signup — no credit card required.

Captions describe both dialogue and non-speech audio — speaker labels ([JOHN]), sound effects ([door slams]), and music cues ([upbeat music]) — designed for viewers who can't hear. Subtitles typically translate or transcribe dialogue only, designed for viewers who can hear but need reading assistance. Regionally: in the US, "captions" usually means accessibility and "subtitles" means translation; in the UK/EU, "subtitles" is used for both. See captions vs subtitles for the deeper breakdown.

For most contexts, yes — with a review pass. Whisper Large-v3 hits 90-95% accuracy on clean audio (studio interviews, produced podcast video, single-speaker explainer), lower on real-world content (Zoom recordings 85-92%, outdoor vlogs 75-85%). WCAG 2.1 Level A requires captions but doesn't specify a numeric accuracy threshold — the informal standard is "captions must convey the audio meaningfully." For US FCC-regulated broadcast, human transcription (Rev, VITAC, 3PlayMedia) is still required; AI captions plus manual review are widely accepted for online video, education, corporate training, and social media.

Four differences. (1) Accuracy transparency: we tell you Whisper Large-v3 hits 90-95% on clean audio and drops on real-world; Canva, VEED, Kapwing claim "99% accuracy" without WER benchmarks. (2) Speaker diarization: we run pyannote.audio 3.1 to label who spoke each line — Canva and CapCut don't. (3) Export flexibility: we export SRT, VTT, TXT, DOCX, JSON, plus burned-in captions. (4) 99 languages: same Whisper model handles English through Yoruba. Canva/Adobe are better if you're already editing in their design suite; CapCut is better if you want TikTok-styled animated captions with emoji. For accuracy-first workflows with universal SRT/VTT export, VexaScribe wins.

Yes, three delivery paths. (1) YouTube: upload the SRT file in YouTube Studio → Subtitles → Add language → Upload file. YouTube indexes the SRT text for search, so uploading a proper SRT beats YouTube's auto-captions for SEO. (2) TikTok / Instagram Reels: these platforms don't reliably support toggleable captions and most viewers watch muted anyway — use burned-in captions (open captions). Export the video with captions burned into the pixels. (3) Vimeo, Wistia, LinkedIn: all support SRT upload. See how to add subtitles to video for platform-by-platform step-by-step.

5-15 minutes of AI processing for a 60-minute video, plus 5-15 minutes of review for proper nouns and speaker labels. Total end-to-end: 10-30 minutes for a 60-minute video. AI runs at 4-10× real-time depending on infrastructure load. For comparison: human captioning services like Rev take 12-48 hour turnaround at $1-3 per audio minute. Self-hosted Whisper Large-v3 on a consumer GPU (RTX 3060+) processes at similar speed to our hosted service, free forever, requires Python + FFmpeg + CUDA setup.

Yes. VexaScribe exports the SRT plus a burned-in MP4 with captions rendered directly into the pixels — permanent, always visible, no separate track. Best for TikTok, Instagram Reels, LinkedIn autoplay video, and any platform where viewers watch muted. Style options: default (white text with dark background box, Netflix convention), or lightweight custom styling (font size, position, color) via the editor. For animated, styled, karaoke-style captions favored by short-form content creators, dedicated tools like Submagic, Captions.ai, or CapCut may fit better — they specialize in that styling niche.

99 languages via Whisper Large-v3. Source language is auto-detected from the audio. Common workflows: Spanish audio → Spanish captions, English audio → English captions plus optional translation to 133 target languages (paid plans), multi-speaker multi-language content → Whisper transcribes each speaker in their language with automatic language switching preserved in the caption file. Accuracy varies by language: Tier 1 (English, Spanish, French, German, Portuguese, Italian, Japanese, Korean, Mandarin) hits 90-95%; smaller languages have higher WER but still functional captions.

30 minutes of video processing free at signup — no credit card, full feature access including SRT/VTT/burned-in export and all 99 languages. Paid plans start at $2/month (Starter, 200 minutes = ~3-4 hour-long videos). Basic ($5/mo, 1000 minutes = ~16 hour-long videos), Pro ($10/mo, 2500 minutes = ~40 hour-long videos), Studio ($20/mo, 6000 minutes = ~100 hour-long videos). Cancel any time. Cheaper than Canva Pro ($15/mo), Adobe Express Premium ($10/mo), and VEED Pro ($18/mo).

No — this is a video accessibility caption generator, not a social-media-caption AI. If you're looking for AI that writes catchy Instagram post captions with hashtags, try Hootsuite, Buffer's AI Assistant, or ChatGPT. VexaScribe's caption generator transcribes the audio in your video into on-screen captions for accessibility, WCAG compliance, and muted-autoplay engagement — different tool for a different job.