OpenAI’s newer transcription stack splits cleanly into two models:
📑Table of Contents
gpt-transcribefor completed audio filesgpt-live-transcribefor live audio that is still arriving
If you ship meeting notes, contact-center recordings, captions, or batch media pipelines, address this split before debating latency or pricing details.
A single wrong proper noun, account ID, or amount can cascade into CRM search failures, incorrect ticket routing, and flawed summarization.
At a glance
What GPT-Transcribe and GPT-Live-Transcribe change
Sources and cutover sequence
This article consolidates the following sources into a practical cutover sequence:
- OpenAI’s Transcription guide and Whisper migration cookbook
- OpenAI Developer Community launch metrics
- Independent write-ups from GIGAZINE, 窓の杜 (Forest), and Microsoft Foundry
The sequence covers model choice, context inputs, non-drop-in gaps, pricing signals, and a fixture checklist.
Recommended starting models
For new integrations, start with this split:
- file transcription →
gpt-transcribe - realtime live audio →
gpt-live-transcribe
OpenAI’s Transcription guide states that mapping in a workflow table.
Streaming output vs live input
Do not confuse streaming output with live input.
- Completed files can stream transcripts without a Realtime session.
- Live microphones and calls map to low-latency
gpt-live-transcribeon the Realtime path.
Microsoft Foundry’s independent write-up uses the same split:
- async: meetings, voicemail, and media
- live: captions, contact center, and accessibility

Legacy models still usable
Legacy options remain usable, but they are not the recommended starting models for new work:
gpt-4o-transcribegpt-4o-mini-transcribegpt-realtime-whisper
You do not need to put every workload on Realtime. Separate high-accuracy batch jobs from low-latency live captions.
How to read launch messaging
Launch messaging emphasizes robustness on:
- short phrases
- numbers
- domain terms
- loud background noise
- accent variation
Treat those claims as directionally useful, then measure your own proper-noun exact-match rates.
Comparison table: file, live, and legacy paths
Classification branch
Classify each workload in one line: completed audio or arriving audio. That line is the model branch.
Primary path matrix
| Workload | Recommended model | Input shape | Strength | Caveat |
|---|---|---|---|---|
| Recorded meetings, voicemail, media | gpt-transcribe | Completed file / batch | Higher accuracy; detected-language metadata | SRT/VTT and word timestamps are not a drop-in |
| Live captions, live mic | gpt-live-transcribe | Continuous Realtime stream | Low latency; tunable delay | Initial contract does not predict detected language |
| Final text after a committed turn | gpt-transcribe after commit | input_audio_buffer.commit |
High-accuracy final chunk | Not the same as continuous live captions |
Legacy path matrix
| Workload | Recommended model | Input shape | Strength | Caveat |
|---|---|---|---|---|
| Subtitles SRT/VTT, word timestamps | keep whisper-1 | File | Existing format compatibility | Not drop-in on the new models |
| English translation | translations endpoint | File | Dedicated translation path | Not a silent model swap |
| Speaker diarization | gpt-4o-transcribe-diarize | File diarized_json | Speaker labels | Not Realtime; long audio needs chunking review |
Sources (as of August 2026)
How to read the matrix
If your product contract still requires subtitle files, word timestamps, translation, or diarization, keep those legacy paths explicit. If the main product output is searchable full text for summarization, center the design on gpt-transcribe.
Context inputs in practice: prompt, keywords, languages
Three separate controls
Accuracy gains come from giving context up front, with three separate controls.
prompt— free-form scene and topic context. Do not restate the whole task.keywords— literal product names, drug names, abbreviations, internal codes. These are hints, not mandatory emissions.languages— expected input languages as an array. Do not send legacy singularlanguageat the same time. For Japanese/English mix, try["ja","en"].
Session context in operations
In Realtime or dedicated transcription sessions, earlier turns can become automatic context for gpt-transcribe. Designing continuous partial captions separately from committed final text makes evaluation cleaner.
What the launch benchmarks show
Community launch numbers show the direction:
- Context Aware ASR semantic accuracy: 38.5% without free-form context → 44.6% with it
- Common Voice across 22 languages: 19.70% error vs 20.33% for GPT-Realtime-Whisper-1
- Real-World Audio across 9 languages: 9.60% vs 11.65%
“Half the errors” headlines are benchmark-context summaries, not a promise on your traffic.
Keyword pitfalls
Two keyword pitfalls matter in production:
- Cookbook validation expects single-line literals. Characters such as
<,>, or newlines can reject the whole request. - Keywords are not a forced lexicon. Inserting a hinted term that was never spoken is keyword hallucination and should fail the gate.
Operationally, put the glossary in keywords, the meeting agenda in prompt, and code-switching expectations in languages. Assign an owner for glossary updates.
Migrating from Whisper without false drop-in assumptions
Three migration paths
Same family of endpoints does not mean the same field and output contracts. The Cookbook (2026-07-28) migration paths are:
- Completed files:
whisper-1→gpt-transcribeonPOST /v1/audio/transcriptions - Continuous live:
gpt-realtime-whisper→gpt-live-transcribevia session.update - High-accuracy after manual commit: Realtime
gpt-transcribeplusinput_audio_buffer.commit
Key contract changes
Key contract changes:
- singular
languagebecomeslanguages[] - vocabulary leaves free-form prompt and moves into structured
keywords - detected language may be
languages:[{code}], or[]when confidence is low - live path exposes
delay(for examplelow) as a partial-text speed vs final-accuracy tradeoff
Non-drop-in capabilities
Non-drop-in capabilities to inventory first:
- SRT/VTT and word timestamps → keep
whisper-1 - English translation → translations endpoint
- Speaker diarization →
gpt-4o-transcribe-diarize
Common mistakes
Common mistakes:
- Treating file streaming output as live microphone input
- Sending
languageandlanguagestogether - Treating empty detected-language
[]as an API failure - Assuming keywords must appear in the transcript
Before cutover, list required response_format, subtitle, diarize, and translation needs, then draw two paths: keep and replace.
Pricing signals and the cutover checklist
Pricing signals by channel
Pricing is channel-specific. Published examples include:
- Independent Japanese coverage (OpenAI API side): about $0.017/min live, $0.0045/min file transcription
- Microsoft Foundry Global Standard examples: about $1.02/hour live, $0.27/hour file audio
Normalize units, then re-check the live price pages for your console before budgeting.
Cutover checklist
Do not cut over on WER alone. A practical checklist looks like this:
- Exact-match scoring for proper nouns, IDs, and numbers
- Fixtures for noise, short utterances, code-switching, and whispering
- Zero keyword hallucination on unsaid hint terms
- Separate TTFT / p95 measurements for file streams and live streams
- A rule for partial-text churn vs stable
item_idcorrelation - Reconnect, empty audio, and interrupted-session cases
- Price and rate-limit math at production traffic
Comparison conditions
Run at least three conditions on a frozen set of 5–10 representative clips:
- baseline (current model)
- model-only (new model, minimal context)
- context-aware (production-like prompt / keywords / languages)
Gate cutover on keyword hallucination and p95 latency against your SLO, not on a single demo clip.
FAQ
Q1. Fastest way to choose between the two models?
Completed audio → gpt-transcribe. Audio arriving now → gpt-live-transcribe.
Q2. What belongs in prompt?
Scene, topic, and participant context in free form. Keep literal term lists in keywords.
Q3. Do keywords force those words into the transcript?
No. They are hints. Emitting unsaid hint terms is a failure mode.
Q4. Can Whisper SRT output move to the new models unchanged?
No. Keep whisper-1 if you still need subtitle formats or word timestamps.
Q5. Is detected language [] an error?
In the Cookbook contract, it is a valid low-confidence result. Do not treat it as a hard failure.
Q6. Are Foundry and direct OpenAI prices identical?
No. Units and channels differ. Always read the current console price table.
Q7. Should you delete gpt-4o-transcribe immediately?
Not necessarily. Existing use can continue. New integrations should start from gpt-transcribe / gpt-live-transcribe.
Summary and next actions
Design takeaway
The durable design is a two-model split plus three context inputs. Read “error rate cut in half” claims as benchmark context, then prove value on your own exact-match and latency gates.
Do this next
- Label each workload completed vs live
- Load glossary →
keywords, agenda →prompt, mixed languages →languages - Keep legacy paths where subtitles, timestamps, translation, or diarization are still required
- Compare baseline / replacement / context-aware on a frozen fixture set and gate on keyword hallucination plus p95
Adjacent reading
For adjacent reading on this site, see the GPT-Live full-duplex product overview, the Grok Voice Agent Builder guide, and Gemini Live Translate coverage for multilingual realtime translation.
Author
krona23
Over 20 years in the IT industry, serving as Division Head and CTO at multiple companies running large-scale web services in Japan. Experienced across Windows, iOS, Android, and web development. Currently focused on AI-native transformation. At DevGENT, sharing practical guides on AI code editors, automation tools, and LLMs in three languages.
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