As of: 2026-11-13 13:49 CET.
Researched and written by AI agents (Claude Opus 5.5 in Claude Code), with a human editor. How we work: https://postcutoff.com/about/
Canonical page: https://postcutoff.com/m/gpt-realtime-1-5/

# GPT-Realtime-1.5

OpenAI, GPT Realtime family. Status: legacy. Type: speech and audio. Released: 2026-02-23. Training cutoff: 2024-09.

## How to call it

| Provider | Model id | Endpoint | Docs |
|---|---|---|---|
| OpenAI API | `gpt-realtime-1.5` | wss://api.openai.com/v1/realtime | https://developers.openai.com/api/docs/models/gpt-realtime-1.5 |

## Pricing

- Text input: $4 per 1M tokens
- Text output: $16 per 1M tokens
- Audio input: $32 per 1M tokens
- Audio output: $64 per 1M tokens
- Cached input: $0.40 per 1M tokens
- Image input: $5 per 1M tokens
- Unit as published: per 1M tokens (USD)
- Source: https://developers.openai.com/api/docs/pricing
- Last checked: 2026-09-29

## Specs

- Input: text, audio, image
- Output: text, audio
- Context window: 32,000 tokens
- Max output: 4,096 tokens
- Open weights: no
- Licence: proprietary

## Where it stands

- Newer speech and audio models in the registry since its release: 65. The 5 newest:
  - NVIDIA Nemotron 3.5 Transcribe (30B-A4B) (2026-10-28) https://postcutoff.com/m/nemotron-3-5-transcribe/
  - Hy-SimulMT-30B-A3B (2026-10-22) https://postcutoff.com/m/hy-simulmt-30b-a3b/
  - Eleven Realtime v1 Max / Mini (2026-10-20) https://postcutoff.com/m/eleven-realtime-v1-max/
  - Voxtral Mini Transcribe 3 (+ Mini Transcribe Realtime 3) (2026-10-20) https://postcutoff.com/m/voxtral-mini-transcribe-3/
  - Voxtral Small Transcribe 3 (2026-10-20) https://postcutoff.com/m/voxtral-small-transcribe-3/
- Before it from OpenAI: GPT-Realtime and GPT-Realtime mini (2025-08-28) https://postcutoff.com/m/gpt-realtime/
- After it from OpenAI: GPT-Realtime-Whisper (2026-05-07) https://postcutoff.com/m/gpt-realtime-whisper/
- Closed weights; access is hosted only.

## What stands out

- Non-reasoning voice agent model: Speech-to-speech model for voice agents and customer support with function calling and prompt caching; cheaper text output ($16 vs $24/1M) than the reasoning gpt-realtime-2.x models. Source: https://developers.openai.com/api/docs/models/gpt-realtime-1.5

## Notes

Released 2026-02-23 alongside gpt-audio-1.5 (Chat Completions). Docs still call it 'our flagship audio model for voice agents', but gpt-realtime-2 (May 2026) and gpt-realtime-2.1 (July 2026) supersede it; not deprecated as of 2026-09-29. It is the named replacement for the gpt-4o-realtime-preview models shut down 2026-05-12.

Sources:
- https://developers.openai.com/api/docs/models/gpt-realtime-1.5
- https://developers.openai.com/api/docs/pricing
- https://developers.openai.com/api/docs/changelog
- https://developers.openai.com/api/docs/deprecations

Model page: https://postcutoff.com/m/gpt-realtime-1-5/