Whisper Transcriber — audio & video to text, SRT & VTT

Send audio or video URLs — or a podcast RSS feed — and get back the transcript: full text, timestamped segments, and ready-to-save SRT + VTT subtitle files. Whisper runs inside the Actor (faster-whisper, int8, CPU), so there is no API key, no external service, and no per-provider markup. 99 languages, auto-detected — accuracy is strongest on well-resourced languages (English, Spanish, Arabic, Russian, …); use the small model for the harder ones. Optional translation to English.

Built for AI agents, podcast pipelines, subtitle workflows, meeting-notes automation and anyone who needs speech as text without wiring up a transcription provider.

What you get

One dataset item per media file:

{
  "url": "https://example.com/episode-42.mp3",
  "episode_title": "Episode 42 — Pricing",
  "status": "ok",
  "model": "base",
  "language": "en",
  "language_probability": 0.994,
  "duration_seconds": 1864.3,
  "billed_minutes": 32,
  "n_segments": 214,
  "n_words": 4930,
  "text": "Full transcript as one string …",
  "segments": [
    { "start": 0.0, "end": 6.48, "text": "Welcome back to the show." }
  ],
  "srt": "1\n00:00:00,000 --> 00:00:06,480\nWelcome back to the show.\n",
  "vtt": "WEBVTT\n\n00:00:00.000 --> 00:00:06.480\nWelcome back to the show.\n"
}

Sources

• Direct media files — mp3, m4a, aac, ogg, opus, wav, flac, mp4, webm and anything else FFmpeg can decode. Up to 250 MB per file.
• Podcast RSS/Atom feeds — the feed URL expands to its newest episodes (Episodes per RSS feed, default 1, up to 10).

Not supported, deliberately: downloading from YouTube, TikTok or other social platforms. Send direct media files you have the right to process.

Pricing — pay only for delivered transcripts

Event	Price	Charged when
file-transcribed	$0.005	a file delivered a non-empty transcript
transcription-minute	$0.008	per started minute of audio transcribed

A 30-minute podcast episode costs $0.245. A one-hour meeting costs $0.485. Compare: hosted transcription APIs charge $0.36–0.90 per hour plus you build the pipeline.

The billing rule is deliberate: files that fail to download, cannot be decoded, or contain no recognizable speech are never billed — not even the per-file fee. If you got no transcript, you pay nothing. Your cost ceiling per file = $0.005 + $0.008 × Max minutes per file (default 120).

Options

Field	Default	Notes
media_urls	—	file URLs and/or RSS feed URLs, up to 25
model	base	tiny / base / small — accuracy vs speed
language	auto	ISO code (en, ar, es, …) skips detection
task	transcribe	translate = English output from any language
rss_episodes	1	newest N episodes per feed
max_minutes_per_file	120	hard cost/length cap; longer files flagged truncated
vad_filter	true	skip silence — faster, fewer hallucinated captions
word_timestamps	false	per-word timing inside segments (slower)

tiny and base are baked into the image and start instantly; small downloads once at the start of the run (~1 minute extra).

Notes on quality

• Voice-activity detection is on by default — silent stretches are skipped instead of becoming hallucinated captions, and long quiet files transcribe much faster.
• For noisy audio, strong accents or lower-resource languages, switch to small — it is the most accurate model offered here.
• Set language explicitly for very short clips; auto-detection has less signal to work with under ~10 seconds.
• translate produces English text directly — no second pass needed.

Limits, stated plainly

• CPU transcription: expect roughly 5–15 seconds of processing per audio minute with base, more with small. Long files take real time; the default run timeout (60 minutes) accommodates a full 2-hour episode with base — raise the run timeout for small on very long files.
• 250 MB per file, 25 URLs per run, 480 minutes max per file.
• Live streams are not supported — the URL must be a finite file.

The family

Actor	Use it for
Whisper Transcriber (this one)	speech in audio/video → text + subtitles
PDF Text Extractor	fast clean text from digital PDFs
PDF OCR Extractor	scanned PDFs, Arabic + English OCR
Doc to Markdown	documents into LLM-ready Markdown

Issues and requests

Open an issue on the actor's Issues tab — I read all of them.