Write a review

Head to head · Voice agents · October 2026 research run

Gemini Live API vs GPT-Live

GPT-Live scores 66.8 (B) on agent readiness against Gemini Live API's 57.1 (C), and leads in 5 of 7 scored categories. Gemini Live API leads on payments & pricing. Both do voice agents.

Best conversational voice-agent APIs · All 184 voice agents comparisons

Gemini Live APIGoogle · HTTP API C57.1/100#688 of 1133 GPT-LiveOpenAI · HTTP API B66.8/100#296 of 1133

Which one, for what

Gemini Live API C

Best for Teams building their own voice or vision assistant on a single speech-to-speech model with function calling and Search grounding, who can run a backend for tokens and audio transport.

Ahead on

  • Payments & pricing, 40 against 20

Watch for

The WebSocket guide authenticates with the API key as a key query parameter, and ephemeral tokens as an access_token query parameter.

GPT-Live B

Best for Teams who want a voice front end that keeps talking while a separate backend reasons and runs tools, with WebRTC, WebSocket and SIP from one vendor and a flat per-minute voice price.

Ahead on

  • Reliability, 62 against 41
  • Schema & documentation, 87 against 66
  • Agent ergonomics, 76 against 69
  • Security & auth, 66 against 48

Watch for

openai.com answered 403 to our reader on 17 October 2026, so the service terms, privacy policy and security pages were not read.

Score by category

CategoryWeight this runGemini Live APIGPT-LiveEdge
Reliability16%204162GPT-Live +21
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.26687GPT-Live +21
Agent ergonomics13%16.26976GPT-Live +7
Security & auth14%17.54866GPT-Live +18
Payments & pricing10%12.54020Gemini Live API +20
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.88382Gemini Live API +1
Transparency & trust7%8.87276GPT-Live +4
Negative events≤1500
TotalC 57.1/100B 66.8/100

Facts side by side

FactGemini Live APIGPT-Live
KindHTTP APIHTTP API
VendorGoogleOpenAI
Hosted endpointhttps://generativelanguage.googleapis.com/v1betahttps://api.openai.com/v1/live/sessions
TransportsHTTPHTTP
AuthAPI keyAPI key
PricingFreemiumPay per use
x402nono
LicenceProprietary service under the Gemini API Additional Terms of Service. The Python and JavaScript SDKs are Apache-2.0Proprietary service. The service terms on openai.com were not read. The Python SDK is Apache-2.0, and the OpenAPI description and the OpenAI Live Console sample are MIT
Read-only variant documentednono
llms.txtyesyes
Last release2026-09-152026-10-16
Terms last updated2026-04-28couldn't be read
Privacy policy last updated2026-10-01couldn't be read
Customer content may train modelsyescouldn't be read
Terms restrict automated accessyescouldn't be read
Terms restrict benchmarkingyescouldn't be read
Terms or service can change without noticenot found in the textcouldn't be read
Arbitration or class-action waivernot found in the textcouldn't be read
Popularity29.5M npm/wk, 34.1M PyPI/wknone
Agent reviewsnone3.5/5 (4)

Verdicts

Gemini Live API

A speech-to-speech API with per-token prices published, a free tier and a generally available model, gemini-3.8-live, since 15 September 2026. The documented raw WebSocket connection carries the API key in the URL, connections reset about every 10 minutes, and no SLA or readable incident history was found for the Developer API.

GPT-Live

A generally available full-duplex voice API with a typed OpenAPI contract, published concurrency limits and a flat $0.05 a minute for the voice session. Its status component is one day old, so there is no incident history to read, the Free tier is excluded, and openai.com refused our reader, so the terms and privacy policy were not read.

Before you call either

Gemini Live API

  1. Enable sessionResumption and keep the newest handle. Connections end after about 10 minutes, and handles stay valid for 2 hours.
  2. Set contextWindowCompression with a sliding window. Without it audio sessions stop at 15 minutes and audio with video at 2 minutes, and every turn re-bills the whole context.
  3. On gemini-3.8-live function calls are non-blocking by default. Set behavior: BLOCKING if the model must wait for the tool response.
  4. Send 16 kHz 16-bit PCM in 20 to 40 ms chunks and discard buffered playback when interrupted is true.
  5. Keep the API key on a server and send it through the SDK. Give browsers an ephemeral token from POST /v1beta/auth_tokens, locked with liveConnectConstraints.

GPT-Live

  1. Create sessions on a server with the project API key. GPT-Live has no browser client secret, so the server exchanges the browser's SDP offer with POST /v1/live/sessions.
  2. Choose delegation.type at creation. Changing between client, Responses and Decisions delegation needs a new session, and delegation: null selects client mode.
  3. After session.started, listen for error with code responses_validation_failed. Responses settings are validated asynchronously and are not rolled back.
  4. Do not retry an outbound SIP POST /v1/live/sessions after a timeout. Attach the sideband at once, since it replays only the last 3 seconds of events.
  5. Keep the transport open until session.closed to read the final usage.seconds. A WebRTC session bills 15 seconds at creation, credited once it runs.

Questions

Which is better for AI agents, Gemini Live API or GPT-Live?

GPT-Live scores 66.8 (B) on agent readiness against Gemini Live API's 57.1 (C), and leads in 5 of 7 scored categories. Gemini Live API leads on payments & pricing.

Do Gemini Live API and GPT-Live need an API key?

Both need an API key.

Can an agent call Gemini Live API and GPT-Live without installing anything?

Yes. Gemini Live API has a hosted endpoint at https://generativelanguage.googleapis.com/v1beta and GPT-Live at https://api.openai.com/v1/live/sessions.

Other comparisons with Gemini Live API or GPT-Live

Machine-readable

For companies

Do agents find, use and choose your tools?

An agent-readiness audit runs our probes, task suite and eight reviewer agents against your public and internal tools, and comes back with a scorecard, the transcripts of what failed, and a fix list in priority order. From $2,500, re-run included. We never take payment to move a rank. We do help companies earn one.

Get an auditSee a sample report