Closed Captioning

Accurate Closed Captions and Transcripts for Course Audio

Convert narration audio into synchronized SRT caption files and text transcripts in seconds. Match your original script for accurate spelling of technical terms, review timing in the browser, and export ready-to-import files for Storyline, Captivate, and other tools.

Generate closed captions

Supports MP3, WAV, and M4A audio files with bulk upload and ZIP export.

Accessibility & Compliance

Make Every Lesson Accessible Without Manual Timecoding

Meeting WCAG 2.1 AA and Section 508 accessibility standards should not require hours of typing timestamps or fixing garbled speech recognition output. Cluelabs uses AI speech recognition paired with intelligent script matching to produce accurate, synchronized caption files ready for your authoring tool in minutes.

Automated speech-to-textConvert spoken course audio into timed subtitle blocks with millisecond precision.
Accurate technical terminologyAlign your original script to the audio so acronyms, brand names, and complex vocabulary are spelled correctly.
Universal authoring compatibilityProduce standard SRT subtitle files that import directly into Articulate Storyline, Adobe Captivate, Camtasia, and video players.
Accessibility by defaultProvide transcripts and captions that support deaf and hard-of-hearing learners, non-native speakers, and noisy study settings.

Script Alignment

Eliminate Speech Recognition Errors with Script Matching

Generic transcription tools frequently stumble over course-specific terminology, specialized product codes, medical terms, and industry acronyms. Cluelabs solves this by letting you provide your original narration script.

Upload or paste your scriptAdd your script as a PDF, Word document, PowerPoint file, Excel sheet, or plain text up to 15MB.
Automated script-to-audio synchronizationAI reads your script text while analyzing the audio waveforms, locking the timing to your exact written words.
Preserve approved punctuationRetain the formal casing, commas, periods, and line breaks established in your instructional design document.
Zero manual proofreadingEliminate hours spent hunting through auto-generated subtitles to fix misheard words and garbled technical terms.

Bulk Processing

Process All Course Audio Files Simultaneously

Never waste time converting audio slide by slide. Cluelabs handles entire courses in parallel so you can move from raw voiceover tracks to finished captions in one streamlined workflow.

Multi-file drag and dropUpload dozens of audio files at once in MP3, WAV, or M4A format.
Automatic file orderingFiles sort automatically by filename, matching your slide numbering scheme from kickoff to completion.
Fast concurrent processingGenerate captions across all files simultaneously in the background.
One-click ZIP downloadDownload every generated SRT file and text transcript in a single organized ZIP archive.

Review & Edit

Review Timing and Edit Captions in the Browser

Verify your captions before exporting them into your authoring software. Our visual editor lets you listen to the audio while checking caption breaks and timecodes.

Built-in audio playerListen to any audio track in the browser while reviewing its corresponding caption lines.
Direct text editingClick into any caption line to rephrase sentences, adjust line breaks, or tweak timestamps directly.
Dual format outputGenerate timed SRT closed captions for slide audio tracks or plain text transcripts for screen-reader documents and job aids.
Instant regenerationMake changes and re-download updated files instantly without re-uploading the original audio.

Authoring Integration

Ready for Articulate Storyline, Captivate, and Video Players

Cluelabs generates standard, compliant caption files that drop straight into your established course development pipeline.

Articulate StorylineImport SRT files directly into Storyline audio tracks with one click, displaying synchronized captions in the modern player.
Adobe CaptivateAttach generated closed captions to slide audio tracks or slide videos for seamless playback.
Video platforms & LMSUpload SRT files alongside MP4 video files in your LMS, Vimeo, or YouTube.
Text transcripts for LMS complianceProvide downloadable text transcripts alongside lessons to satisfy corporate accessibility audits.

Production Workflow

How to Generate Closed Captions

Upload Course Audio

Drag and drop your MP3, WAV, or M4A narration files for one slide or an entire module.
Select Language & Provide Script

Choose the narration language and optionally attach your approved script for automated quality matching.
Review in the Browser

Listen to the audio with the built-in player and make any quick adjustments to text or timing in the editor.
Export SRT or ZIP

Download individual SRT files or export all course captions at once in an organized ZIP archive.

Common Questions

Frequently Asked Questions

How does script matching improve caption accuracy?

Standard speech-to-text algorithms transcribe purely from sound, which frequently leads to misheard technical words, acronyms, or proper names. When you provide your approved narration script, Cluelabs uses the script as the authoritative text and uses AI to align the timestamps to each word. This guarantees 100% accurate spelling and punctuation while keeping precise timing.

Which audio formats and file sizes are supported?

You can upload MP3, WAV, and M4A audio files up to 16MB per file. You can select multiple files at once or drag and drop an entire folder of course audio.

Can I process audio for an entire course at once?

Yes. You can upload all audio tracks for a complete course simultaneously. Cluelabs processes them in batches and lets you download all finished SRT files in a single ZIP archive.

How do I import the generated SRT files into Articulate Storyline?

In Storyline, select your audio track on the slide timeline, click the Options tab on the ribbon, and choose Add Captions. Select the generated SRT file, and Storyline will automatically display the synchronized closed captions in the course player.

What languages are supported for captioning and transcription?

Cluelabs supports dozens of languages and regional dialects, including English, Spanish, French, German, Mandarin Chinese, Japanese, Portuguese, Italian, Dutch, and Arabic.

Can I generate plain text transcripts in addition to SRT caption files?

Yes. During processing, you can choose whether you need timed closed captions (SRT) or clean text transcripts (TXT). Transcripts are ideal for creating downloadable study guides, accessibility handouts, and LMS lesson summaries.

Get Started

Create Accessible Captions for Your Courses Today

Upload your narration audio, align your scripts, and download synchronized SRT caption files in minutes.