Simplify your closed caption workflows
Transcribe, translate, convert, and deliver closed captioning using a single API.
Trusted by broadcasters and streaming platforms worldwide
Plugins & connectors
Build more powerful caption workflows by connecting Closed Caption Converter directly to the services you already use.
Our API connectors let you leverage your existing accounts with leading transcription, translation, storage, and platform providers. Reduce costs while gaining capabilities that go far beyond what these services offer alone.
| Service provider | Type | Comments |
|---|---|---|
| Deepgram | Transcription | Support for Transcription and Sync |
| Assembly AI | Transcription | Support for Transcription and Sync |
| Speechmatics | Transcription | Support for Transcription and Sync |
| RevAI | Transcription | Support for Transcription and Sync |
| AWS S3 | Storage | Deliver files to S3 Storage |
| Google Cloud Storage | Storage | Deliver files to Google Cloud Storage using dedicated service account |
| Backblaze B2 | Storage | Deliver files to Backblaze B2 (using S3 driver) |
| Azure Blob Storage | Storage | Deliver files to Azure Blob Storage |
| DeepL | Translation | Full translation support with continuous context |
| ModernMT | Translation | Full translation support with continuous context |
| Google Translate | Translation | Full translation support with continuous context |
| Amazon Translate | Translation | Full translation support with continuous context |
| Gemini | Translation | Full translation support with continuous context |
| OpenAI | Translation | Full translation support with continuous context |
| Azure AI Translator | Translation | Full translation support with continuous context |
| Iconik MAM | Platform | Read and write subtitle files from Iconik MAM. Sync, transcribe, and translate media from Iconik. |
| Closed Caption Creator | Platform | Register projects in Closed Caption Creator for users to manually review and edit. |
Transcription & alignment (sync)
Generate accurate captions with your preferred speech-to-text provider.
Turn audio into broadcast-ready captions using industry-leading transcription services like Deepgram, Assembly AI, Speechmatics, or RevAI—all through a single API call. While these providers excel at speech recognition, they typically output raw JSON transcripts that aren’t suitable for broadcast delivery. Our connectors handle the complete workflow: transcribe using your provider account at their direct rates, then automatically convert results into properly formatted SCC, SRT, WebVTT, or any caption format your delivery specs require. We’ll handle timecode alignment, caption block segmentation, and format-specific validation so you get production-ready files, not just transcripts.
Developer information
Transcription service providers support both transcribe (audio-to-text) and align (sync existing text to audio) job types. Configure your provider in the transcribe_options object, and pass provider-specific parameters through provider_options.
...
"job_type" : "transcribe",
"transcribe_options" : {
"source_language" : "en",
"provider_id" : "transcription_provider_id",
"provider_options" : {
//PROVIDER OPTIONS ARE PASSED THROUGH
"model" : "general",
"tier" : "nova",
"punctuate" : true,
"diarize" : false,
"utterances" : true,
"utt_split" : 0.8
}
},
......
"job_type" : "transcribe",
"transcribe_options" : {
"source_language" : "en",
"provider_id" : "transcription_provider_id",
"provider_options" : {
//PROVIDER OPTIONS ARE PASSED THROUGH
"speaker_labels" : true
}
},
......
"job_type" : "transcribe",
"transcribe_options" : {
"source_language" : "en",
"provider_id" : "transcription_provider_id",
"provider_options" : {
//PROVIDER OPTIONS ARE PASSED THROUGH
"operating_point": "enhanced",
"diarization": "speaker"
}
},
......
"job_type" : "align",
"transcribe_options" : {
"source_language" : "en",
"provider_id" : "transcription_provider_id",
"provider_options" : {
//PROVIDER OPTIONS ARE PASSED THROUGH
"model" : "general",
"tier" : "nova",
"punctuate" : true,
"diarize" : false,
"utterances" : true,
"utt_split" : 0.8
}
},
"media_path": "https://presigned-url-to/media.mp4",
...Provider options are passed directly to the transcription service. Refer to your provider’s API documentation for available parameters and their supported values. The media_path for alignment jobs must be a publicly accessible or presigned URL to your media file.
Machine translation
Translate subtitles while preserving context and broadcast formatting.
Deliver multilingual content faster by connecting to translation engines like DeepL, Google Translate, Gemini, ModernMT, OpenAI, or Amazon Translate. Translating subtitle files presents unique challenges—long captions must be split intelligently, context needs to carry across caption blocks, and timing constraints must be respected. Our translation connectors manage this complexity for you: we intelligently batch captions to preserve context, handle character-per-second limitations for different languages, maintain proper formatting and positioning codes, and ensure the translated output meets broadcast technical specifications. Get professional-quality translated subtitle files in one job, not the fragmented results you’d get from passing raw text to a translation API.
Developer information
Translation service providers require a translate job type and are configured in the translate_options object. Specify your provider using the provider_id from your dashboard, along with source and target language codes supported by your chosen provider. Language codes are passed through directly to the provider.
...
"job_type" : "translate", //!important
"translate_options" : {
"provider_id" : "translation_provider_id",
"source_language": "en", //use language codes based on provider support
"target_language": "it" //use language codes based on provider support
},
...Storage
Deliver outputs directly to your cloud infrastructure.
Streamline your delivery pipeline by connecting Closed Caption Converter directly to your cloud storage. Add your S3, Azure Blob Storage, Backblaze B2, or Google Cloud Storage account, and have all job outputs automatically delivered to your specified buckets and paths. No need to retrieve files from our servers and re-upload them to your infrastructure—we’ll write directly to your storage with proper folder structures, naming conventions, and metadata. Perfect for automated workflows where caption files need to land alongside video assets, trigger downstream processes, or integrate with your existing media management infrastructure.
Developer information
Storage service providers are configured in the delivery_options object of your job request. Specify your provider using the provider_id you created in the dashboard, then pass provider-specific configuration through provider_options.
...
"delivery_options": {
"provider_id": "service_provider_id",
"provider_options": {
"bucket" : "bucket-name",
"region" : "us-east-2",
"key" : "path/to/file.srt"
}
}
......
"delivery_options": {
"provider_id": "gcs_provider_id",
"provider_options": {
"projectId" : "your-project-id",
"clientEmail" : "username@demo-app.iam.gserviceaccount.com",
"bucket" : "gcs-bucket-name",
"fileName" : "filename.srt"
}
}
......
"delivery_options": {
provider_id": "azure_provider_id",
"provider_options": {
"container" : "container-name",
"blobName" : "fileName.srt"
}
}
...Platform
Integrate caption workflows into your media asset management systems and professional editors.
Connect your caption processing directly into the platforms where your content lives. Our Iconik MAM connector reads subtitle files from assets, processes them through any Converter workflow, and writes results back to the same asset—all without leaving your MAM environment. The Closed Caption Creator connector goes a step further: automatically register processed caption files as review projects that your captioning team can access, edit, and refine in our professional editor. These platform integrations eliminate manual file transfers and create seamless handoffs between automated processing and human review, keeping your entire workflow connected and traceable.
Developer information
Platform service providers integrate caption workflows directly into your media asset management and editing systems. Like storage providers, they deliver output files, but they also interact with the platform’s API to register files and maintain associations within your asset database.
Iconik MAM
The Iconik connector enables seamless caption processing within your Iconik environment. When configured, Closed Caption Converter automatically reads subtitle files from assets, processes them according to your job specifications, and writes the results back to the original asset.
Setup & configuration
- Configure your Iconik Platform connector in the Closed Caption Converter dashboard
- Create a Custom Action in Iconik that posts to the Closed Caption Converter
/iconikendpoint - Trigger jobs directly from Iconik assets—no additional API configuration required
POST https://api.closedcaptionconverter.com/iconikWhen a job is submitted through the /iconik endpoint, Closed Caption Converter automatically:
- Reads the asset context and associated subtitle files
- Processes the caption file according to your job parameters
- Re-associates the output file(s) with the original Iconik asset
- Updates asset metadata to reflect the completed workflow
Need help setting up the Iconik integration? Contact our support team for assistance with Custom Action configuration.
One engine, three ways to use it
Start with our simple web application for fast conversions, scale with our cloud API for automated processing and third-party integrations, or deploy our CLI for on-premise and offline processing.
Web Application
Need to convert a few caption files quickly? Our web application runs entirely in your browser with no downloads or uploads required. Your files stay secure on your device while processing happens locally—just select, convert, and download.
API
The most advanced closed caption API available, with features beyond conversion. Add transcription, machine translation, forced alignment/sync, and direct delivery to cloud storage and managed platforms such as Iconik.
CLI
Built for secure, on-premise environments where internet access is restricted. Available for Mac, Windows, and Linux. This single file executable is easy to deploy and manage using custom presets.
Ready to get started?
Sign up for a free 7-day trial of Closed Caption Converter and get 1:1 developer support and access to our video tutorials.
Start automating your closed caption workflows. Convert, conform, and deliver closed caption files in over 30 different formats.