Best OpenAI Models for RAG

Match · Updated July 2026

The best OpenAI model for RAG is GPT-5.6 Sol — 58.9 intelligence with 1.1M tokens of context for retrieved passages. GPT-5.6 Terra (55.0) and GPT-5.5 (54.8) round out the top three.

58.9Intelligence

74 t/sSpeed

$5.00Input /M

1.1MContext

The best AI models for retrieval-augmented generation, ranked by intelligence among models with at least 128K tokens of context — enough to hold retrieved passages plus conversation. RAG pipelines run at volume, so weigh the price and speed columns as hard as the score.

Frequently asked

What is the best OpenAI model for RAG?

The best OpenAI model for RAG is GPT-5.6 Sol — 58.9 intelligence with 1.1M tokens of context for retrieved passages. GPT-5.6 Terra (55.0) and GPT-5.5 (54.8) round out the top three.

What's a good alternative to GPT-5.6 Sol?

GPT-5.6 Terra (55.0) is the closest alternative on this metric, followed by GPT-5.5 (54.8). See the full ranking above for the tradeoffs.

How many OpenAI models are there?

modelgrep tracks 67 OpenAI models with live benchmarks, speed, latency and per-provider pricing, led on intelligence by GPT-5.6 Sol. 25 of them qualify for this ranking.

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All rankings

Small & Fast LLMs Best Local LLMs Smartest LLMs Best LLMs for Coding Best LLMs for Design & Frontend Fastest LLMs Lowest-Latency LLMs Cheapest LLMs Best Free LLMs Best Reasoning LLMs Best Vision LLMs Best LLMs for Agents Best Open-Source LLMs Longest-Context LLMs Best LLMs for Writing Best LLMs for Math & Science Best LLMs for SQL & Data Analysis Best LLMs for Roleplay Best Uncensored LLMs