Best AI Model for RAG & Knowledge Base Q&A
Retrieval-augmented generation for answering questions from documents, wikis, and knowledge bases.
Our Verdict
Gemini 2.5 Flash at $0.15/$0.60 with 1M context is the RAG sweet spot — large context means fewer chunks needed, and the price per query is tiny. For higher accuracy on complex retrieved content, GPT-5 at $1.25/$10 gives more precise answers. If budget is critical, DeepSeek V3 at $0.14/$0.28 handles simple Q&A over retrieved chunks well. For RAG, input cost dominates — you're sending 5-20 chunks per query.
Top Picks
1M context at $0.15 input — large context reduces chunking needs
Best for: Cost-effective RAG at scale
Input
$0.15/1M
Output
$0.6/1M
Context
1M
Max Output
66K
Strong accuracy on complex retrieved content at moderate pricing
Best for: High-accuracy RAG
Input
$1.25/1M
Output
$10/1M
Context
128K
Max Output
16K
Input
$0.14/1M
Output
$0.28/1M
Context
164K
Max Output
16K
What Matters for RAG
Key Factors
- •Context window
- •Input cost
- •Accuracy on retrieved text
- •Speed
Tips
- ✓Input cost is crucial — RAG sends lots of retrieved chunks per query
- ✓Larger context windows reduce the need for aggressive chunking
- ✓Budget models handle simple Q&A well; use flagships for complex reasoning over retrieved docs
Full Ranking (All Compatible Models)
| Rank | Model | Input | Output | Avg Bench | Score |
|---|---|---|---|---|---|
| #1 | Gemini 2.5 FlashGoogle | $0.15 | $0.60 | 82.8% | 123 |
| #2 | Gemini 3 FlashGoogle | $0.50 | $3.00 | 84.0% | 91 |
| #3 | DeepSeek V3DeepSeek | $0.14 | $0.28 | 83.5% | 86 |
| #4 | Gemini 2.5 ProGoogle | $1.25 | $10.00 | 85.7% | 82 |
| #5 | Llama 4 MaverickMeta | $0.31 | $0.85 | 85.3% | 82 |
| #6 | Llama 4 ScoutMeta | $0.18 | $0.63 | 80.1% | 82 |
| #7 | GLM-4.7Zhipu AI | $0.60 | $2.20 | 85.0% | 74 |
| #8 | Gemini 3.1 ProGoogle | $2.00 | $12.00 | 93.4% | 70 |
| #9 | Gemini 3 ProGoogle | $2.00 | $12.00 | 86.9% | 70 |
| #10 | GPT-5OpenAI | $1.25 | $10.00 | 85.7% | 68 |
| #11 | MiniMax M2.5MiniMax | $0.30 | $1.20 | 86.0% | 67 |
| #12 | GPT-4o MiniOpenAI | $0.15 | $0.60 | 77.6% | 66 |
| #13 | o3OpenAI | $0.40 | $1.60 | 86.9% | 66 |
| #14 | Mistral Medium 3Mistral | $0.40 | $2.00 | 81.5% | 63 |
| #15 | DeepSeek R1DeepSeek | $0.55 | $2.19 | 82.5% | 62 |
| #16 | o4-miniOpenAI | $1.10 | $4.40 | 84.8% | 59 |
| #17 | GLM-5Zhipu AI | $1.00 | $3.20 | 77.8% | 58 |
| #18 | Claude Haiku 4.5Anthropic | $0.80 | $4.00 | 78.8% | 58 |
| #19 | GPT-4oOpenAI | $2.50 | $10.00 | 78.6% | 50 |
| #20 | GPT-5.2 CodexOpenAI | $1.75 | $14.00 | 86.8% | 48 |
| #21 | Claude Sonnet 4.6Anthropic | $3.00 | $15.00 | 83.3% | 48 |
| #22 | Claude Sonnet 4.5Anthropic | $3.00 | $15.00 | 81.9% | 48 |
| #23 | Mistral Large 3Mistral | $2.00 | $5.00 | 87.0% | 47 |
| #24 | GPT-5.3 CodexOpenAI | $2.00 | $16.00 | 88.2% | 47 |
| #25 | Grok 4xAI | $3.00 | $15.00 | 83.7% | 36 |
| #26 | Claude Opus 4.6Anthropic | $5.00 | $25.00 | 86.7% | 32 |