Why teams evaluate this API
Designed for products that need timed lyrics, captions, karaoke data, searchable transcripts, or subtitle input for downstream video workflows.
Audio-to-Timed-Text
Audio transcription and subtitle timing API
Extract lyrics, line-level and word-level timing, and production-ready subtitle files from public audio URLs.
10 / 60s$0.02/min default public priceAudio Minutes
Best-fit teams
- • Music and karaoke products that need synchronized lyrics
- • Creator tools exporting SRT, VTT, LRC, or JSON timing
- • Media pipelines that need timed text before video composition
Core capabilities
- • Lyrics extraction with line-level and word-level timestamps
- • SRT and JSON output by default, with optional VTT and LRC artifacts
- • Automatic source-duration detection for quote and task sizing
- • Asynchronous status, webhook delivery, idempotency, and signed downloads
Typical implementation flow
- 1Request a quote or let the service inspect the audio duration
- 2Create an idempotent subtitle extraction task
- 3Poll the task or receive a webhook when processing completes
- 4Read lyrics and timing, then download the requested subtitle artifacts
Timed-text outputs and duration pricing
A task returns extracted lyrics plus line- and word-level timing. SRT and JSON are the default artifacts; VTT and LRC can be requested in the same operation.
- Input
- Public HTTPS audio URL
- Duration
- Up to 10 minutes
- Outputs
- Lyrics, timeline, SRT, JSON, VTT, LRC
- Retention
- 7 days by default
How the charge is calculated
The current catalog reference is $0.02 per audio minute. At the runtime conversion rate, that is 10 credits per unit, prorated to whole credits with a 1-credit minimum.
credits = max(1, ceil(durationSec / 60 × 10))The default $0.05/minute value is a client safety cap. It is not the public price. Lowering it below the quoted rate rejects the request before paid work starts.
The reference figure comes from the live quote catalog. The charged amount is credits, so the effective USD cost depends on the credit package shown in the table.
| Audio length | Credits | Starter | Pro | Enterprise |
|---|---|---|---|---|
| 30 seconds | 5 | $0.0143 | $0.0125 | $0.01 |
| 1 minute | 10 | $0.0286 | $0.025 | $0.02 |
| 3 minutes | 30 | $0.0857 | $0.075 | $0.06 |
| 10 minutes | 100 | $0.2857 | $0.25 | $0.20 |
POST /api/v1/subtitles/quote → POST /api/v1/subtitlesView Subtitle Sync pricingFAQ
How is Subtitle Sync billed?
Billing is prorated by actual audio duration and rounded up to whole credits with a minimum charge. Use the Quote API for the current amount before creating a task.
Which files can the API generate?
Every task can return lyrics and structured timing. SRT and JSON are the defaults; VTT and LRC can be requested in the same task.
Can Subtitle Sync feed a music-video workflow?
Yes. The managed MV workflow can use the same timed-text pipeline when an audio source does not already include aligned lyrics.
Is the duration hint required?
No. The service can inspect a supported public audio source before quoting or creating the task. Supplying a known duration can make a quote request faster.