ƒ Curated ranking

Cheapest AI models with function calling

Models that natively support function or tool calling — foundational for building agents, RAG with structured retrieval, or any LLM workflow that needs to invoke external systems. Ranked by input price ascending.

Methodology

How this ranking is built

Active models with verified function-calling support and a published input price. Ranked from cheapest input cost upward.

# Model Provider Input price Lifecycle Verified
1
gpt-oss-20b
OpenAI · Active
OP OpenAI $0.03/M input Active · 45m ago
2
Amazon Nova Micro
AWS Bedrock · Active
AB AWS Bedrock $0.04/M input Active · 1h ago
3
gpt-oss-120b
OpenAI · Active
OP OpenAI $0.04/M input Active · 46m ago
4
GPT-5 Nano
OpenAI · Active
OP OpenAI $0.05/M input Active · 47m ago
5
o3
OpenAI · Active
OP OpenAI $0.06/M input Active · 45m ago
6
Amazon Nova Lite
AWS Bedrock · Active
AB AWS Bedrock $0.06/M input Active · 1h ago
7
GPT-4.1 Nano
OpenAI · Active
OP OpenAI $0.1/M input Active · 48m ago
8
Gemini 2.0 Flash
Google Gemini · Active
GG Google Gemini $0.1/M input Active · 57m ago
9
Gemini 2.5 Flash-Lite
Google Gemini · Active
GG Google Gemini $0.1/M input Active · 56m ago
10
Llama 3.3 70B
Meta · Active
ME Meta $0.1/M input Active
11
GPT-4o Mini
OpenAI · Active
OP OpenAI $0.15/M input Active · 48m ago
12
Llama 4 Maverick
Meta · Active
ME Meta $0.15/M input Active
13
GPT-5.4 Nano
OpenAI · Active
OP OpenAI $0.2/M input Active · 46m ago
14
GPT-5 Mini
OpenAI · Active
OP OpenAI $0.25/M input Active · 48m ago
15
Gemini 3.1 Flash-Lite
Google Gemini · Active
GG Google Gemini $0.25/M input Active · 55m ago
16
Gemini 2.5 Flash
Google Gemini · Active
GG Google Gemini $0.3/M input Active · 56m ago
17
GPT-4.1 Mini
OpenAI · Active
OP OpenAI $0.4/M input Active · 48m ago
18
GPT-5.4 Mini
OpenAI · Active
OP OpenAI $0.75/M input Active · 46m ago
19
Claude Haiku 3.5
Anthropic · Active
AN Anthropic $0.8/M input Active · 1h ago
20
Amazon Nova Pro
AWS Bedrock · Active
AB AWS Bedrock $0.8/M input Active · 1h ago
21
Claude Haiku 4.5
Anthropic · Active
AN Anthropic $1/M input Active · 1h ago
22
Grok Build 0.1
xAI · Active
XA xAI $1/M input Active · 43m ago
23
o4-mini
OpenAI · Active
OP OpenAI $1.1/M input Active · 44m ago
24
GPT-5
OpenAI · Active
OP OpenAI $1.25/M input Active · 48m ago
25
GPT-5.1
OpenAI · Active
OP OpenAI $1.25/M input Active · 47m ago
Showing top 25 of 49 matches. Refreshed as we re-verify each model against its provider's official docs. Every value links to the page it came from. Last updated Jun 15, 2026 17:57 UTC.