300 models ranked for API and backend development. Function calling and JSON mode are critical for building reliable services. Scored with heavy bonuses for these capabilities.
| # | Model | Score |
|---|---|---|
| 1 | GPT-5.4 ProOpenAI | 94 |
| 2 | GPT-5.4OpenAI | 94 |
| 3 | GPT-5.4 MiniOpenAI | 93 |
| 4 | GPT-5.2 ProOpenAI | 93 |
| 5 | GPT-5.2OpenAI | 93 |
| 6 | Claude Opus 4.6Anthropic | 92 |
| 7 | GPT-5 ProOpenAI | 92 |
| 8 | o3 Deep ResearchOpenAI | 92 |
| 9 | Claude Opus 4.5Anthropic | 90 |
| 10 | GPT-5OpenAI | 90 |
| 11 | Gemini 3 Flash PreviewGoogle | 89 |
| 12 | Claude Sonnet 4.6Anthropic | 89 |
| 13 | Claude Sonnet 4.5Anthropic | 89 |
| 14 | o3 ProOpenAI | 88 |
| 15 | Grok 4.1 FastxAI | 87 |
| 16 | Grok 4.20 BetaxAI | 86 |
| 17 | Grok 4xAI | 86 |
| 18 | Gemini 3.1 Pro PreviewGoogle | 86 |
| 19 | o3OpenAI | 86 |
| 20 | GPT-5.1OpenAI | 85 |
| 21 | MiMo-V2-OmniXiaomi | 85 |
| 22 | MiMo-V2-ProXiaomi | 85 |
| 23 | GPT-5.4 NanoOpenAI | 85 |
| 24 | Seed-2.0-LiteByteDance | 85 |
| 25 | Qwen3.5-9BAlibaba | 85 |
| 26 | Seed-2.0-MiniByteDance | 85 |
| 27 | Gemini 3.1 Pro Preview Custom ToolsGoogle | 85 |
| 28 | GPT-5.3-CodexOpenAI | 85 |
| 29 | Qwen3.5 Plus 2026-02-15Alibaba | 85 |
| 30 | Kimi K2.5Moonshot AI | 85 |
JSON mode ensures reliable structured output for generating OpenAPI specs, database schemas, and type definitions. Models understand REST, GraphQL, and gRPC patterns.
Generate endpoint handlers, middleware, validation logic, and test suites. Large context windows let models understand your entire service architecture for consistent code.
Function calling models understand tool invocation patterns. They help design and implement API integrations with third-party services, SDKs, and webhooks.
Reasoning models analyze query patterns, identify N+1 problems, suggest caching strategies, and audit endpoints for security vulnerabilities like injection and IDOR.
Based on our composite scoring updated hourly, the top-ranked models are shown at the top of this page. Rankings consider benchmarks, pricing, capabilities, and community adoption.
Yes, several models listed on this page offer free tiers or are fully open-source. Look for models marked as Free in the pricing column above.
We use a composite scoring system combining benchmark performance, capability matching, pricing, context window size, and community adoption. Scores are updated hourly.
Rankings refresh every hour using real-time data from benchmarks, API testing, and community metrics. The data shown always reflects the most current performance.