GPT-Realtime-1.5 vs GPT-Realtime-2.1 Mini: price, context and capabilities

Choose GPT-Realtime-2.1 Mini for the lowest price and very long inputs; on the other points the two are level or the data is missing.

In short

  • GPT-Realtime-2.1 Mini is 69% cheaper than GPT-Realtime-1.5 at the headline price ($10.00 / 1M audio tokens vs $32.00 / 1M audio tokens).
  • GPT-Realtime-2.1 Mini reads more per request: 128k tokens against 32k.
  • Only GPT-Realtime-2.1 Mini offers reasoning.

Open in the full comparison table

Which should you choose?

Each answer below comes straight from the published prices, specifications and independent benchmark results.

Lowest price

Choose GPT-Realtime-2.1 Mini

GPT-Realtime-2.1 Mini costs $10.00 / 1M audio tokens, against $32.00 / 1M audio tokens for GPT-Realtime-1.5.

Very long inputs

Choose GPT-Realtime-2.1 Mini

GPT-Realtime-2.1 Mini reads up to 128k tokens per request, against 32k for GPT-Realtime-1.5.

Specifications side by side

GPT-Realtime-1.5GPT-Realtime-2.1 Mini
ProviderOpenAIOpenAI
CategoryVoice and realtimeVoice and realtime
StatusLegacyGenerally available
Headline price$32.00 / 1M audio tokens$10.00 / 1M audio tokens
Context window32k128k
Max output4k32k
ReleasedFeb 23, 2026No data
Knowledge cutoffSeptember 2024September 2024
LicenceProprietaryProprietary
CapabilitiesAudio input, Tool callingAudio input, Reasoning, Tool calling
API model idgpt-realtime-1.5gpt-realtime-2.1-mini

Frequently asked questions

Should I choose GPT-Realtime-1.5 or GPT-Realtime-2.1 Mini?

Choose GPT-Realtime-2.1 Mini for the lowest price and very long inputs; on the other points the two are level or the data is missing.

Which is cheaper, GPT-Realtime-1.5 or GPT-Realtime-2.1 Mini?

GPT-Realtime-2.1 Mini is 69% cheaper than GPT-Realtime-1.5 at the headline price ($10.00 / 1M audio tokens vs $32.00 / 1M audio tokens).

Which has the larger context window, GPT-Realtime-1.5 or GPT-Realtime-2.1 Mini?

GPT-Realtime-2.1 Mini reads more per request: 128k tokens against 32k.

What is the difference between GPT-Realtime-1.5 and GPT-Realtime-2.1 Mini?

GPT-Realtime-1.5 is made by OpenAI and GPT-Realtime-2.1 Mini by OpenAI. GPT-Realtime-2.1 Mini is 69% cheaper than GPT-Realtime-1.5 at the headline price ($10.00 / 1M audio tokens vs $32.00 / 1M audio tokens). GPT-Realtime-2.1 Mini reads more per request: 128k tokens against 32k. Only GPT-Realtime-2.1 Mini offers reasoning.