AI Model Context Window Comparison 2025 | Generated by AI
Here’s a clearer take—without a table—on context window sizes of the models you listed:
Leading Context Windows
Gemini-2.5-Pro Google’s Gemini 2.5 Pro offers a 1 million token context window—and even plans to expand to 2 million tokens soon (Google AI for Developers, blog.google). This is currently the largest among the models mentioned.
Claude Models (Anthropic family)
- Claude‑3 Opus (and family such as Sonnet) initially offered 200 k tokens, with capabilities exceeding 1 million for select users (Reddit, Wikipedia).
- On paid plans, the context window remains 200 k+ tokens (about 500 pages) (Anthropic Help Center).
- Sonnet 4 on Enterprise plans offers up to 500 k tokens (Anthropic Help Center).
- And, via the Claude Code API, Claude 4 Sonnet may support 1 million tokens (ClaudeLog).
So maximum context:
- Standard Claude Opus 4: ~200 k tokens.
- Sonnet 4 (Enterprise): up to 500 k tokens.
- Claude 4 Sonnet via API (Claude Code): up to 1 million tokens.
GPT-5 (OpenAI)
- OpenAI officially states 256 k tokens context window for GPT‑5 (WIRED, Amazon Web Services, Inc., Anthropic Help Center).
- Some sources suggest the free ChatGPT interface supports 256 k tokens, while API variants may go higher—but no confirmed 1M tokens for GPT‑5 (Cinco Días).
- Community reports mention an upper bound speculation but documentation seems to settle at 256 k (OpenAI Community, Encord).
Other Models
- Gemini-Flash likely has the same large context window as other Gemini models (1 million+), but details specifically for “Flash” aren’t confirmed.
- Other listed models—like “kimi-k2”, “deepseek-v3/x”, “mistral-medium”, “qwen-coder”, and “gpt-oss”—are not prominently documented regarding context window size in the sources I found. Likely they offer more standard ranges (e.g., <200 k), though without explicit confirmation.
Bottom Line
- Largest context window overall: Gemini 2.5 Pro (1 million tokens, expanding to 2 million)
- Close runner-up: Claude 4 Sonnet via API (~1 million tokens)
- Then: GPT-5 (~256 k tokens)
- Followed by: standard Claude models (~200 k tokens), with Sonnet 4 Enterprise bumping to 500 k tokens.
Let me know if you’d like deeper details on any particular model—happy to help without long tables, promise!