How do you use this tool?
- Click the upload area or drag and drop an English audio file (MP3, WAV, M4A, OGG, WebM).
- Pick a quality tier: Fast (~93 MB, mobile-friendly) or Accurate (~188 MB, desktop recommended).
- Click Transcribe. The model loads into your browser cache once, then works offline forever after.
- Watch the real-time factor: values below 1.0× mean the tool is faster than the audio length.
- Copy the transcript or download it as TXT (plain text) or SRT (with timestamps for subtitles).
Why a dedicated tool for English-only audio?
English is by far the most-transcribed language — podcasts, tech talks, international meetings, YouTube tutorials. Multi-language speech-recognition models have to carry tokenisers, vocabularies and language-identification weights for around 100 languages. That bloats the download, the memory footprint and the inference time — even when you only speak English.
A model trained exclusively on English drops all of that overhead. The decoder shrinks to roughly half the size, inference becomes measurably faster. On identical hardware the Fast tier processes audio below real-time — a ten-minute podcast often finishes in 90 seconds. The multi-language audio transcription tool at its Accurate tier takes three to four times as long for the same recording.
How does in-browser transcription work?
The pipeline runs in two stages, both on your device:
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Decode and normalise. The Web Audio API decodes your file and resamples it to 16 kHz mono — the input format speech-recognition models expect. Stereo channels are averaged to a single mono signal.
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Inference. A compact neural network compiled to WebAssembly converts each 30-second window of audio into text tokens, then merges the windows into a continuous transcript with timestamps. Everything runs inside your browser tab — no cloud API, no third-party service.
The model is downloaded once on first use and cached in your browser. After that, transcription works fully offline.
Two quality tiers — which to pick?
The choice trades download size against recognition accuracy:
| Tier | Model size | Best for |
|---|---|---|
| Fast | ~93 MB | Short memos, calls under 30 minutes, mobile devices |
| Accurate | ~188 MB | Long lectures, accented audio, noisy recordings |
Pick a tier in the model selector below the upload area. Each tier is cached separately, so you can switch back and forth.
What does the real-time factor mean?
After every transcription a real-time factor appears in the result area. It shows how long processing took relative to the audio length:
- <1.0× — faster than the audio (e.g. 0.4× = 40% of the audio length).
- 1.0× — processing took as long as the audio.
- >1.0× — processing was slower than real-time.
On modern laptops with the Fast tier, clear recordings typically land between 0.3× and 0.6×. Long recordings, loud background noise or older hardware push the value higher. On older phones even the Fast tier may run above 1.0× — split into shorter segments to keep the browser responsive.
How is privacy guaranteed?
The tool never contacts an external server. No account, no signup, no consent to data sharing. Close the tab and nothing remains — not locally, not in any cloud. That makes the tool especially well-suited for:
- Confidential conversations — recruiting interviews, legal consultations, doctor recordings.
- NDA content — internal meetings, strategy calls, product briefings.
- Journalistic sources — interview recordings without third-party access.
- Academic research — GDPR-friendly, no data-processing agreement required.
TXT or SRT — which export?
The download dialog offers two formats:
- TXT — plain running text, one paragraph. Best for meeting minutes, blog drafts, research notes.
- SRT — SubRip subtitle format with start/end timestamps per block (
00:01:23,456 --> 00:01:28,910). Imports directly into YouTube, Premiere Pro, DaVinci Resolve, CapCut, VLC.
For social-video subtitles, download SRT and import it into your editor — font, size and position are rendered by the player.
What are the best-practice tips?
- Quiet environment beats post-processing filters every time.
- Mic distance 20–30 cm reduces plosives and distortion.
- Speak deliberately — slow, clear delivery boosts recognition, especially for technical vocabulary.
- Split long recordings into 30–60-minute chunks before transcribing — more stable and gives natural break points.
- 128 kbps MP3 is plenty for transcription. Higher bitrates don’t improve accuracy.
What are common use cases?
Podcast show notes. Transcribe a full episode to pull quotes, build timestamped chapters, or write an SEO-friendly description. A one-hour podcast typically produces a 5,000–8,000-word transcript.
English meetings & calls. International standups, customer interviews with US/UK clients, English investor calls — quickly produce a transcript without exposing sensitive content to external transcription services.
Video captions. English-language tutorials, reels or lecture recordings: SRT export gives you the base you only need to spell-check in the editor. Improves accessibility for deaf viewers and silent autoplay on social.
Academic research. Qualitative researchers transcribe English-language expert interviews without sending sensitive data to a third-party transcription service — GDPR-friendly, no DPA required.
Which related tools help next?
From the kittokit ecosystem for the full audio-to-text workflow:
- Audio Transcription — For German, French, Spanish or mixed-language recordings. Larger model, but multi-language.
- Speech Enhancer — Remove noise, echo and background hum before transcribing. Translates directly into higher word accuracy.
- Text Diff — Compare two transcript versions, e.g. raw vs. proofread. Highlights changes word-by-word.
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