Best Long Context LLM APIs (200K+ tokens)

Processing entire codebases, long documents, or extended conversations requires LLM APIs with large context windows. Here are the best options in 2026.

Gemini 2.5 Pro

Google

Price: Free (within limits)
Context: 1,048,576
Key: Largest context window, multimodal, free tier available

DeepSeek V4 Pro

DeepSeek

Price: $1.74/$3.48 per M in/out
Context: 1,000,000
Key: 1M context at low cost, strong reasoning

GPT-4.1

OpenAI

Price: $2/$8 per M in/out
Context: 1,047,576
Key: 1M context, excellent for code agents

Kimi K2.6

Moonshot AI

Price: $0.95/$4 per M in/out
Context: 262,144
Key: Large context at competitive pricing

Claude Sonnet 4.6

Anthropic

Price: $3/$15 per M in/out
Context: 200,000
Key: Strong retrieval accuracy, tool use

GPT-5.4

OpenAI

Price: $2.5/$15 per M in/out
Context: 272,000
Key: Latest GPT generation, strong all-around

Prices and availability subject to change. Affiliate disclosure.