Jamba 1.5 Large vs Claude Sonnet 5
Claude Sonnet 5 for quality. Jamba 1.5 Large for 256K context tasks at lower cost.
AI21's Jamba 1.5 Large ($2.00/M input) is 33% cheaper than Claude Sonnet 5 ($3.00/M) and offers a 256K context window. Jamba uses a hybrid SSM-transformer architecture that makes it efficient for very long-document tasks. On standard reasoning benchmarks, Sonnet 5 leads by 10-15%. The use case that makes Jamba interesting: processing long documents efficiently at moderate cost.
Side-by-side pricing
| Jamba 1.5 Large | Claude Sonnet 5 | |
|---|---|---|
| Provider | AI21 Labs | Anthropic |
| Input price/1M | $2.00 | $3.00 |
| Output price/1M | $8.00 | $15.00 |
| Cache read/1M | — | $0.30 |
| Context window | 256K | 200K |
| Vision | ✗ | ✓ |
| Tool use | ✓ | ✓ |
| Prompt caching | ✗ | ✓ |
| Speed tier | Medium | Standard |
Prices verified 2026-08-20. See changelog for history.
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Frequently Asked Questions
What is AI21 Jamba's SSM architecture?
Jamba uses a hybrid of Mamba (State Space Model) layers and standard transformer attention layers. SSM layers are computationally more efficient than attention for long sequences — O(n) vs O(n²) complexity. This makes Jamba particularly fast and memory-efficient for very long inputs, though quality on standard benchmarks slightly lags pure-transformer models.
Prices verified 2026-08-20. See methodology for calculation details.