Feature

Auto Subtitle Generator
Powered by Whisper AI

Generate accurate, timestamped subtitles from any video — SRT, VTT, burned-in MP4, or DOCX. Whisper AI detects the spoken language automatically across 100+ languages. Pay per minute, credits never expire.

check_circle1 credit per minutecheck_circleCredits never expirecheck_circleNo subscription required

Capto uses OpenAI Whisper — the most accurate automatic speech recognition model available — to generate frame-perfect subtitles from any video file. Upload an MP4, MOV, WebM, AVI, or MKV and receive a fully timestamped transcript in under two minutes, complete with word-level timestamps for karaoke-style highlighting. Whisper detects the spoken language automatically, supporting 100+ languages without any configuration. The resulting transcript is fully editable in Capto’s workspace before you export. Pay only for what you use: transcription costs 1 credit per minute, and credits never expire.

95%+
Transcription accuracy with Whisper AI
100+
Languages detected automatically
< 2 min
From upload to timestamped transcript
$0.03
Per minute of video transcribed

What’s included

  • graphic_eqOpenAI Whisper — 95%+ accuracy on clear audio
  • languageAutomatic language detection across 100+ spoken languages
  • record_voice_overMulti-speaker diarization — labels each speaker automatically (1.5× credits)
  • scheduleWord-level karaoke timestamps — each word highlights as it's spoken
  • edit_noteFully editable transcript — fix any segment inline before exporting
  • downloadExport as SRT, VTT, TXT, DOCX, or burned-in MP4
  • upload_fileSupports MP4, MOV, WebM, AVI, and MKV video files
  • bolt1 credit per minute — credits never expire, no subscription required
  • styleCaption style presets — custom fonts, colors, positions, and backgrounds
  • emoji_emotionsAuto emoji overlay — GPT-4o adds contextual emojis to captions

Who is the auto subtitle generator for?

Anyone who produces video with spoken content — but these three groups use it most.

school

Educators and course creators

Lecture recordings and instructional videos become more accessible when every word is searchable and readable. Capto turns a 45-minute lecture into a timestamped transcript in roughly 2 minutes, ready to upload to your LMS as captions or export as a DOCX for students who prefer reading. SRT files slot directly into Teachable, Thinkific, and Kajabi without any reformatting.

video_camera_front

YouTube and social video creators

85% of social video is watched without sound. Accurate, frame-timed captions keep viewers engaged and improve watch time — a direct ranking signal on YouTube. Capto's burned-in MP4 export bakes captions directly into the video file, so they appear automatically on Instagram Reels, TikTok, and X without requiring a separate subtitle track on each platform.

mic

Podcasters

Podcast episodes on YouTube, Spotify Video, or your own site benefit from subtitle files for both SEO and accessibility. Capto's multi-speaker diarization labels each host and guest separately, making transcripts easier to read and repurpose for show notes. Export TXT or DOCX for your blog, or SRT to upload directly to the platform.

How the auto subtitle generator works

When you upload a video, Capto extracts the audio track and compresses it to a lightweight mono MP3 before sending it to Whisper in optimised segments. This keeps processing fast even for long videos — a 60-minute upload becomes roughly a 10 MB audio file. Whisper returns a timestamped transcript with timing down to the individual word. For multi-speaker content, enabling diarization routes the audio through an additional speaker-separation model before transcription, at a 1.5× credit multiplier.

The transcript lands in Capto’s workspace editor. Word-level timestamps power the karaoke-style subtitle preview — each word highlights as it’s spoken. Edit any segment inline, then export. The same corrected transcript drives every format: SRT for YouTube, VTT for your web player, burned-in MP4 for social platforms, DOCX for show notes.

STEP 01
Upload your video
MP4, MOV, WebM, AVI, or MKV. Drag & drop or browse. Every new account includes 5 free minutes — no credit card required to try.
STEP 02
Whisper detects language and transcribes
Capto extracts a compressed audio track and sends it to OpenAI Whisper. The spoken language is identified automatically across 100+ languages. Word-level timestamps are generated alongside the transcript.
STEP 03
Review and edit in the workspace
Click any subtitle segment to edit the text inline. The video plays alongside and jumps to whichever segment you click — corrections take seconds, not minutes.
STEP 04
Export in any format
SRT for YouTube, VTT for your web player, TXT or DOCX for show notes, or a burned-in MP4 with captions permanently embedded. Edit once, export everywhere.

Why Whisper AI?

OpenAI trained Whisper on 680,000 hours of multilingual audio — a dataset roughly 10× larger than competing open models. That scale gives it two meaningful advantages: it handles accented speech and technical vocabulary far better than most alternatives, and it identifies the spoken language from the audio itself rather than requiring you to declare it upfront.

Most speech-to-text services return segment-level timestamps — one timestamp per subtitle block. Whisper returns word-level timestamps, which is what powers Capto’s karaoke-style preview and makes burned-in MP4 exports look professional rather than mechanical. Words appear in sync with speech, not in chunks.

Cloud alternatives like Google Speech-to-Text and AWS Transcribe charge per second of audio on top of your own service fees. Capto bundles Whisper into the credit cost — 1 credit per minute of video, nothing extra for transcription.

100+ spoken languages, detected automatically

Whisper identifies the spoken language from the audio with no manual selection required. After transcription, you can translate subtitles into 60+ target languages — including Spanish, French, Arabic, Japanese, Hindi, German, Portuguese, Korean, Italian, Russian, and Chinese — with four tone presets.

EnglishSpanishFrenchGermanJapaneseChineseArabicHindiPortugueseKoreanItalianRussianDutchPolishSwedishTurkishGreekThaiVietnameseIndonesianRomanianCzechDanishFinnishNorwegianUkrainianHebrewBengaliMalayCatalan+ 70 more

Plan limits

All plans accept the same video formats: MP4, MOV, WebM, AVI, and MKV. The differences between plans are file size cap, maximum video length per upload, and how many export jobs can run simultaneously. Credits are shared across all operations and never expire.

PlanMax file sizeMax video lengthConcurrent exports
Essential100 MB15 min1
Creator500 MB60 min2
Pro500 MB120 min3
Growth2 GB4 hr5

Need longer videos or larger files? View all plans →

Frequently asked questions

How accurate is an auto subtitle generator?add

Capto uses OpenAI Whisper, which achieves 95%+ accuracy on clear, single-speaker audio — comparable to professional human transcription for most content. Accuracy drops in noisy environments or when speakers overlap. Enabling multi-speaker diarization separates overlapping speakers before transcribing, which helps. Every segment is editable in Capto's workspace so you can fix the rare error before exporting.

Can I edit auto-generated subtitles after transcription?add

Yes. Capto's workspace lets you click any subtitle segment and edit the text inline. Changes apply immediately to every export format — SRT, VTT, TXT, DOCX, and burned-in MP4. You can also adjust start and end timestamps per segment. The video plays alongside the editor and jumps to the segment you're editing, so corrections take seconds rather than minutes.

What video and subtitle formats are supported?add

Any common video container works: MP4 (H.264 or H.265), MOV, WebM, AVI, and MKV are all accepted. For subtitle output, Capto exports SRT (compatible with YouTube, Vimeo, and most video players), VTT (the HTML5 standard for browser-based players and LMS platforms), TXT (plain transcript without timestamps), DOCX (formatted Word document for show notes), and burned-in MP4 (captions permanently embedded in the video frame). All formats are generated from the same workspace in one click.

How long does subtitle generation take?add

Most videos are transcribed in under 2 minutes regardless of length. Capto extracts a compressed mono MP3 before sending audio to Whisper — a 30-minute video becomes roughly 5 MB rather than 500 MB. Videos with speaker diarization enabled may take up to 4 minutes. Processing time does not affect credit cost: you are charged 1 credit per minute of video duration, not per minute of processing time.

Is there a free trial for the auto subtitle generator?add

Yes — every new Capto account starts with 5 free credits (enough to transcribe a 5-minute video), no credit card required. That covers a short tutorial, podcast clip, or conference excerpt. Credit packs start at $4 for 120 credits (120 minutes of transcription). Credits never expire, so unused minutes carry forward indefinitely.

Does the auto subtitle generator work for non-English videos?add

Yes. Whisper automatically detects the spoken language from the audio — no manual selection needed. It covers 100+ languages including Spanish, French, German, Japanese, Chinese, Arabic, Hindi, Portuguese, Korean, Italian, and Russian. After transcription, Capto's translation feature can produce subtitle files in 60+ target languages with four tone options: formal, casual, educational, and creative.

Generate subtitles in under 2 minutes

Every new account starts with 5 free minutes. No credit card required.

boltStart Free — 5 min included

Related features

translate
Video Translation
Translate your subtitles into 60+ languages with four tone presets. One click from the workspace — no re-upload needed.
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Captions for TikTok
Burn word-level karaoke captions into a 9:16 MP4, ready to post to TikTok or Instagram Reels in under 2 minutes.
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Add Subtitles to YouTube
Step-by-step: generate an SRT with Capto, then upload the subtitle track directly in YouTube Studio.

From the blog

How to add subtitles to a video →How to add subtitles to online course videos →