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.

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#	Model	Provider	Input price	Lifecycle	Verified
1	Amazon Nova Micro AWS Bedrock · Active	AB AWS Bedrock	$0.04/M input	Active	· 11h ago
2	GPT-5 Nano OpenAI · Active	OP OpenAI	$0.05/M input	Active	· 11h ago
3	Amazon Nova Lite AWS Bedrock · Active	AB AWS Bedrock	$0.06/M input	Active	· 11h ago
4	Gemini 2.0 Flash Google Gemini · Active	GG Google Gemini	$0.1/M input	Active	· 11h ago
5	Gemini 2.5 Flash-Lite Google Gemini · Active	GG Google Gemini	$0.1/M input	Active	· 11h ago
6	GPT-4o Mini OpenAI · Active	OP OpenAI	$0.15/M input	Active	· 11h ago
7	GPT-5.4 Nano OpenAI · Active	OP OpenAI	$0.2/M input	Active	· 11h ago
8	GPT-5 Mini OpenAI · Active	OP OpenAI	$0.25/M input	Active	· 11h ago
9	Gemini 3.1 Flash-Lite Google Gemini · Active	GG Google Gemini	$0.25/M input	Active	· 11h ago
10	Gemini 2.5 Flash Google Gemini · Active	GG Google Gemini	$0.3/M input	Active	· 11h ago
11	GPT-4.1 Mini OpenAI · Active	OP OpenAI	$0.4/M input	Active	· 11h ago
12	GPT-5.4 Mini OpenAI · Active	OP OpenAI	$0.75/M input	Active	· 11h ago
13	Claude Haiku 3.5 Anthropic · Active	AN Anthropic	$0.8/M input	Active	· 11h ago
14	Amazon Nova Pro AWS Bedrock · Active	AB AWS Bedrock	$0.8/M input	Active	· 11h ago
15	Claude Haiku 4.5 Anthropic · Active	AN Anthropic	$1/M input	Active	· 11h ago
16	Grok Build 0.1 xAI · Active	XA xAI	$1/M input	Active	· 11h ago
17	o4-mini OpenAI · Active	OP OpenAI	$1.1/M input	Active	· 11h ago
18	GPT-5 OpenAI · Active	OP OpenAI	$1.25/M input	Active	· 11h ago
19	GPT-5.1 OpenAI · Active	OP OpenAI	$1.25/M input	Active	· 11h ago
20	Gemini 2.5 Pro Google Gemini · Active	GG Google Gemini	$1.25/M input	Active	· 11h ago
21	Grok 4.20 xAI · Active	XA xAI	$1.25/M input	Active	· 11h ago
22	Grok 4.3 xAI · Active	XA xAI	$1.25/M input	Active	· 11h ago
23	Gemini 3.5 Flash Google Gemini · Active	GG Google Gemini	$1.5/M input	Active	· 11h ago
24	GPT-5.2 OpenAI · Active	OP OpenAI	$1.75/M input	Active	· 11h ago
25	GPT-4.1 OpenAI · Active	OP OpenAI	$2/M input	Active	· 11h ago

Showing top 25 of 43 matches.

Methodology

How this ranking is built

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

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 3, 2026 19:38 UTC.