AI Context Window Comparison (2026): GPT, Claude, Gemini Token Limits by Model#
When developers search for context window limits, they usually want one thing: a clear comparison table. This guide shows the practical token limits for major models in 2026.
Context Window Comparison Table#
| Model | Context Window | Best For |
|---|---|---|
| GPT-5.4 | 128K | General app workflows |
| Claude Opus 4.7 | 200K | Complex reasoning, long documents |
| Claude Sonnet 4.5 | 200K | Coding, writing, large context |
| Claude Haiku 4.5 | 200K | Fast extraction, classification |
| Gemini Pro | 1M+ | Extremely long documents, multimodal context |
| Gemini Flash | 1M+ | Fast long-context processing |
| Kimi K2 | 128K+ | Chinese reasoning |
| Qwen 2.5 | 128K | Budget-friendly long context |
| DeepSeek V3 | 128K | Cost-efficient long docs |
What Does Context Window Actually Mean?#
The context window is the maximum amount of text (measured in tokens) a model can process at once. Larger context windows matter when you are working with:
- Full codebases
- Long contracts or reports
- Multi-document RAG workflows
- Large chat histories
- PDF analysis
Which Model Should You Choose?#
| Need | Recommended Model |
|---|---|
| Best balance of quality and long context | Claude Sonnet |
| Strongest reasoning over long docs | Claude Opus |
| Largest context possible | Gemini Pro |
| Cheapest long-context option | DeepSeek / Qwen |
| Chinese long-context work | Kimi K2 |
Access Through Crazyrouter#
All major long-context models are available through Crazyrouter.
python
from openai import OpenAI
client = OpenAI(
api_key="sk-your-crazyrouter-key",
base_url="https://crazyrouter.com/v1"
)
response = client.chat.completions.create(
model="claude-sonnet-4-5-20250929",
messages=[
{"role": "user", "content": "Summarize this 100-page document..."}
]
)
FAQ#
Does larger context always mean better performance?#
No. A larger context window lets you send more text, but model quality still matters. Gemini has the largest context, but Claude often performs better on reasoning quality.
How many words is 200K tokens?#
Roughly 150,000 words in English, depending on formatting and language.
Which model is best for codebase analysis?#
Claude Opus and Sonnet are usually the best balance of context size and code quality.
Related#
Implementation Guides
List ModelsQuery models available to the current API key through GET /v1/models.Claude Native FormatCall Claude through the Anthropic Messages API on Crazyrouter.Reasoning ModelsChoose the right protocol and fields for thinking and reasoning workloads.Quick Start GuideMake the first Crazyrouter API call and validate your setup.
