High-volume, cost-sensitive work
Choose Claude Opus 5.5
Claude Opus 5.5 costs 29% less on a typical mix of three input tokens for every output token ($8.00 against $11.25 per million tokens).
Chat Latest vs Claude Opus 5.5: price, context and capabilities
Choose Claude Opus 5.5 for high-volume, cost-sensitive work, writing and code generation, reused prompts and documents (RAG, agents), very long inputs, the latest release and the most recent knowledge; on the other points the two are level or the data is missing.
In short
- Claude Opus 5.5 is 29% cheaper than Chat Latest at the headline price ($8.00 / 1M tokens vs $11.25 / 1M tokens).
- Claude Opus 5.5 reads more per request: 1M tokens against 400k.
- Claude Opus 5.5 is the newer model (September 2026, against May 5, 2026).
- Only Claude Opus 5.5 offers reasoning.
Which should you choose?
Each answer below comes straight from the published prices, specifications and independent benchmark results.
Writing and code generation
Choose Claude Opus 5.5
Claude Opus 5.5 charges $20.00 per million output tokens, against $30.00 for Chat Latest. Output dominates the bill when answers are long.
Reused prompts and documents (RAG, agents)
Choose Claude Opus 5.5
Claude Opus 5.5 charges $0.20 per million cached input tokens, against $0.50 for Chat Latest.
Very long inputs
Choose Claude Opus 5.5
Claude Opus 5.5 reads up to 1M tokens per request, against 400k for Chat Latest.
Latest release
Choose Claude Opus 5.5
Claude Opus 5.5 is the newer release (September 2026, against May 5, 2026 for Chat Latest).
Most recent knowledge
Choose Claude Opus 5.5
Claude Opus 5.5 was trained on data up to June 2026, against April 2026 for Chat Latest.
Monthly cost at three volumes
| Volume | Chat Latest | Claude Opus 5.5 | Difference |
|---|---|---|---|
| Prototype: 1M input, 250K output tokens | $12.50 | $9.00 | Claude Opus 5.5, $3.50 less |
| Production: 20M input, 5M output tokens | $250.00 | $180.00 | Claude Opus 5.5, $70.00 less |
| Scale: 500M input, 100M output tokens | $5,500 | $4,000 | Claude Opus 5.5, $1,500 less |
Standard rates, without caching or batch discounts. Volumes are per month.
Specifications side by side
| Chat Latest | Claude Opus 5.5 | |
|---|---|---|
| Provider | OpenAI | Anthropic |
| Category | Language models | Language models |
| Status | Generally available | Generally available |
| Headline price | $11.25 / 1M tokens | $8.00 / 1M tokens |
| Input | $5.00 / 1M tokens | $4.00 / 1M tokens |
| Output | $30.00 / 1M tokens | $20.00 / 1M tokens |
| Cached input | $0.50 / 1M tokens | $0.20 / 1M tokens |
| Context window | 400k | 1M |
| Max output | 128k | 128k |
| Released | May 5, 2026 | September 2026 |
| Knowledge cutoff | April 2026 | June 2026 |
| Licence | Proprietary | Proprietary |
| Capabilities | Vision, Tool calling, Structured output, Prompt caching, Batch API | Vision, Reasoning, Tool calling, Structured output, Prompt caching, Batch API |
| API model id | chat-latest | claude-opus-5-5 |
Benchmarks side by side
Leader in bold.
| Benchmark | Chat Latest | Claude Opus 5.5 |
|---|---|---|
| Intelligence Index | No data | 57.6 |
| SciCode | No data | 66.9% |
| Humanity's Last Exam | No data | 61.4% |
| MMMU-Pro (visual reasoning) | No data | 87.7% |
| Long-context reasoning (AA-LCR) | No data | 84.7% |
Independent evaluations by Artificial Analysis, run the same way for every model, at the reasoning setting shown. Percentages unless marked as an index.
Frequently asked questions
Should I choose Chat Latest or Claude Opus 5.5?
Choose Claude Opus 5.5 for high-volume, cost-sensitive work, writing and code generation, reused prompts and documents (RAG, agents), very long inputs, the latest release and the most recent knowledge; on the other points the two are level or the data is missing.
Which is cheaper, Chat Latest or Claude Opus 5.5?
Claude Opus 5.5 is 29% cheaper than Chat Latest at the headline price ($8.00 / 1M tokens vs $11.25 / 1M tokens).
Which has the larger context window, Chat Latest or Claude Opus 5.5?
Claude Opus 5.5 reads more per request: 1M tokens against 400k.
What is the difference between Chat Latest and Claude Opus 5.5?
Chat Latest is made by OpenAI and Claude Opus 5.5 by Anthropic. Claude Opus 5.5 is 29% cheaper than Chat Latest at the headline price ($8.00 / 1M tokens vs $11.25 / 1M tokens). Claude Opus 5.5 reads more per request: 1M tokens against 400k. Claude Opus 5.5 is the newer model (September 2026, against May 5, 2026). Only Claude Opus 5.5 offers reasoning.
How much do Chat Latest and Claude Opus 5.5 cost per month?
At 20 million input and 5 million output tokens a month, Chat Latest costs $250.00 and Claude Opus 5.5 costs $180.00, at standard rates.
Which is newer, Chat Latest or Claude Opus 5.5?
Claude Opus 5.5 was released on September 2026 and Chat Latest on May 5, 2026.