Models

GPT 4o Search Preview vs GPT 5.6 Luna

Compare GPT 4o Search Preview from OpenAI and GPT 5.6 Luna from OpenAI on key metrics including benchmarks, price, context length, and other model features. Access both models and hundreds of others through the AIHubMix API.

OpenAIGPT 4o Search PreviewOpenAIGPT 5.6 Luna
OpenAI logo
GPT 4o Search Preview
OpenAI · text, image → text

Using the Chat Completions API, you can directly access the fine-tuned models and tool used by Search in ChatGPT. When using Chat Completions, the model always retrieves information from the web before responding to your query. To use web_search_preview as a tool that models like gpt-4o and gpt-4o-mini invoke only when necessary, switch to using the Responses API. Currently, you need to use one of these models to use web search in Chat Completions: gpt-4o-search-preview gpt-4o-mini-search-preview Web search parameter example import OpenAI from "openai"; const client = new OpenAI(); const completion = await client.chat.completions.create({ model: "gpt-4o-search-preview", web_search_options: {}, messages: [{ "role": "user", "content": "What was a positive news story from today?" }], }); console.log(completion.choices[0].message.content); Output and citations The API response item in the choices array will include: message.content with the text result from the model, inclusive of any inline citations annotations with a list of cited URLs By default, the model's response will include inline citations for URLs found in the web search results. In addition to this, the url_citation annotation object will contain the URL and title of the cited source, as well as the start and end index characters in the model's response where those sources were used.

Input$2.5 /M
Output$10 /M
Cache read$1.25 /M
OpenAI logo
GPT 5.6 Luna
OpenAI · text, image → text

GPT-5.6 Luna is designed for cost-sensitive, high-volume workloads. It roughly corresponds to the nano model tier used in earlier GPT-5 families.

Input$1 /M
Output$6 /M
Cache read$0.1 /M

Pricing & Specifications

Prices are per million tokens. Time to First Token and throughput are rolling averages measured on AIHubMix.

GPT 4o Search Preview
GPT 5.6 Luna
Input /M
$2.5
$1
Output /M
$10
$6
Cache read /M
$1.25
$0.1
Context length
NaN
1,050,000
Max output
0
128,000
Time to First Token
2.3 s
2.2 s
Throughput
120.9 tok/s
88.4 tok/s
Modalities
textimage
textimage
Supported Parameters
webfunction callingstructured outputs
toolsthinkingstructured outputs
API Formats
chat_completions · responses
Released
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Promotional prices show the discounted rate; see each model page for promotion windows.

Activity Past 30 Days

Daily traffic served through AIHubMix — how demand for each model is trending.

gpt-4o-search-previewgpt-5.6-luna

Tokens / day

-

Requests / day

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Performance Past 3 Days

Measured on real AIHubMix traffic, hourly buckets. Gaps mean no traffic in that hour.

gpt-4o-search-previewgpt-5.6-luna

Throughput (tok/s)

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TTFT (s)

-

Uptime (%)

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Cost calculator

Estimate your monthly bill for the same workload on each model.

GPT 5.6 Luna
$150 /mo
GPT 4o Search Preview
$300 /mo

Monthly = daily × 30. Discounted rates applied where a promotion is active.

FAQ

Which is cheaper: GPT 4o Search Preview, GPT 5.6 Luna?

GPT 5.6 Luna: $6/M output tokens; GPT 4o Search Preview: $10/M. Use the cost calculator above to estimate your own workload.

Which responds faster?

GPT 5.6 Luna: 2.2s time to first token measured on AIHubMix; see the live performance charts above for how each model behaves across the day.

Which one generates tokens faster?

GPT 4o Search Preview at 120.9 tok/s and GPT 5.6 Luna at 88.4 tok/s, measured as output throughput on AIHubMix — a separate metric from time to first token.

What inputs and capabilities does each model support?

GPT 4o Search Preview accepts text and image input and supports web search, function calling and structured outputs; GPT 5.6 Luna accepts text and image input and supports tool calling, thinking and structured outputs.

Can I call GPT 4o Search Preview and GPT 5.6 Luna with the same API key?

Yes. AIHubMix serves every model on this page behind one OpenAI-compatible endpoint, so switching between them is a one-line change to the model field — no second account, key or SDK.

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