Choose AI21: Jamba Large 1.7 if…
- cost matters at scale — it is 83% cheaper on a typical 3:1 input/output mix ($310 vs $1,750 a month for 50,000 support chats)
AI21: Jamba Large 1.7 vs Claude Opus 5 (Fast)
Neither wins outright: AI21: Jamba Large 1.7 is the pick when cost matters at scale, Claude Opus 5 (Fast) when you need to fit long inputs in one request.
Key numbers
| Spec | AI21: Jamba Large 1.7 | Claude Opus 5 (Fast) |
|---|---|---|
| Provider | AI21 | Anthropic |
| Input price (per 1M tokens) | $2.00 | $10.00 |
| Output price (per 1M tokens) | $8.00 | $50.00 |
| Blended price (3:1 input/output) | $3.50 | $20.00 |
| Cheaper than … of all models we track | 18% | 3% |
| Context window | 256K tokens (~384 pages) | 1M tokens (~1,500 pages) |
| Larger context than … of all models | 45% | 69% |
| Max output per response | 4K tokens (~3,100 words) | 128K tokens (~96,000 words) |
| Input types | text | text, image, file |
| Output types | text | text |
| Free variant | No | No |
| Listed since | 2025-08-08 | 2026-07-24 |
Advertisement
What it costs for real workloads
Monthly cost at list price for five common workloads. Token counts per unit are stated so you can scale them to your own traffic. A workload that does not fit a model's context window is marked rather than priced.
| Workload (per month) | AI21: Jamba Large 1.7 | Claude Opus 5 (Fast) | Difference |
|---|---|---|---|
| Customer-support chatbot 50,000 conversations — each a 6-turn conversation (1,500 in / 400 out tokens) | $310 | $1,750 | AI21: Jamba Large 1.7 saves $1,440 |
| RAG search over documents 20,000 questions — each a question answered from ~8 retrieved passages (6,000 in / 500 out tokens) | $320 | $1,700 | AI21: Jamba Large 1.7 saves $1,380 |
| Coding / tool-using agent 2,000 tasks — each a multi-step task with tool calls and file context (60,000 in / 6,000 out tokens) | $336 | $1,800 | AI21: Jamba Large 1.7 saves $1,464 |
| Batch summarisation 10,000 documents — each a 6,000-word report summarised to a page (8,000 in / 600 out tokens) | $208 | $1,100 | AI21: Jamba Large 1.7 saves $892 |
| Long-document analysis 500 documents — each a 150-page contract or codebase read in one pass (100,000 in / 2,000 out tokens) | $108 | $550 | AI21: Jamba Large 1.7 saves $442 |
Capabilities side by side
| Capability | AI21: Jamba Large 1.7 | Claude Opus 5 (Fast) | What it lets you do |
|---|---|---|---|
| Tool / function calling | ✓ Yes | ✓ Yes | call your APIs and run agent loops |
| Structured output (JSON schema) | ✓ Yes | ✓ Yes | return JSON that validates against your schema |
| Reasoning / thinking mode | — | ✓ Yes | spend extra tokens thinking before answering hard problems |
| Image input | — | ✓ Yes | read screenshots, charts and scanned pages |
| Audio input | — | — | take speech or audio directly |
| File / PDF input | — | ✓ Yes | accept documents without your own parsing step |
| Image output | — | — | generate images, not just text |
| Built-in web search | — | ✓ Yes | answer from live web results |
| Seed (reproducible sampling) | — | — | repeat a generation for tests and evals |
| Log-probabilities | — | — | read token confidence for classification and scoring |
From each model's published parameters and input/output types. “—” means not advertised, not proven absent.
Price history
- AI21: Jamba Large 1.7: price unchanged since we started tracking it on 2026-03-10.
- Claude Opus 5 (Fast): price unchanged since we started tracking it on 2026-08-06.
Which should you choose?
Choose Claude Opus 5 (Fast) if…
- you need to fit long inputs in one request — 1M tokens is roughly 1,500 pages, against 384
- you need reasoning / thinking mode — to spend extra tokens thinking before answering hard problems; AI21: Jamba Large 1.7 does not advertise it
- you need image input — to read screenshots, charts and scanned pages; AI21: Jamba Large 1.7 does not advertise it
- you need file / PDF input — to accept documents without your own parsing step; AI21: Jamba Large 1.7 does not advertise it
- you need built-in web search — to answer from live web results; AI21: Jamba Large 1.7 does not advertise it
- you generate long outputs in one go — up to 128K tokens (about 96,000 words) per response
- you want the newer model — released 2026-07-24, 12 months after the other
Frequently asked questions
Is AI21: Jamba Large 1.7 better than Claude Opus 5 (Fast)?
Neither wins outright: AI21: Jamba Large 1.7 is the pick when cost matters at scale, Claude Opus 5 (Fast) when you need to fit long inputs in one request. In short: AI21: Jamba Large 1.7 when cost matters at scale; Claude Opus 5 (Fast) when you need to fit long inputs in one request, you need reasoning / thinking mode, you need image input, you need file / PDF input, you need built-in web search, you generate long outputs in one go, you want the newer model.
Which is cheaper, AI21: Jamba Large 1.7 or Claude Opus 5 (Fast)?
AI21: Jamba Large 1.7 is cheaper: $3.50 vs $20.00 per 1M tokens at a typical 3:1 input/output mix, 83% less. For 50,000 support conversations a month that is $310 against $1,750.
How much do AI21: Jamba Large 1.7 and Claude Opus 5 (Fast) cost per million tokens?
AI21: Jamba Large 1.7 costs $2.00 per 1M input tokens and $8.00 per 1M output tokens; Claude Opus 5 (Fast) costs $10.00 input and $50.00 output. Output tokens are billed separately, so long answers shift the gap.
Which has the bigger context window, AI21: Jamba Large 1.7 or Claude Opus 5 (Fast)?
Claude Opus 5 (Fast): 1M tokens, about 1,500 pages, against 256K (about 384 pages) for AI21: Jamba Large 1.7.
Do AI21: Jamba Large 1.7 and Claude Opus 5 (Fast) support function calling and JSON output?
Tool calling — AI21: Jamba Large 1.7: yes, Claude Opus 5 (Fast): yes. JSON-schema structured output — AI21: Jamba Large 1.7: yes, Claude Opus 5 (Fast): yes.
Can AI21: Jamba Large 1.7 or Claude Opus 5 (Fast) read images?
Only Claude Opus 5 (Fast) accepts image input; AI21: Jamba Large 1.7 is text-only for input.
Is AI21: Jamba Large 1.7 or Claude Opus 5 (Fast) free to use?
No free variant is listed for either; both are pay-per-token.
What is the maximum output length of AI21: Jamba Large 1.7 and Claude Opus 5 (Fast)?
AI21: Jamba Large 1.7 can write up to 4K tokens (about 3,100 words) per response; Claude Opus 5 (Fast) up to 128K (about 96,000 words).
When were AI21: Jamba Large 1.7 and Claude Opus 5 (Fast) released?
AI21: Jamba Large 1.7 was listed on 2025-08-08; Claude Opus 5 (Fast) on 2026-07-24.
About the two models
AI21: Jamba Large 1.7
Jamba Large 1.7 is the latest model in the Jamba open family, offering improvements in grounding, instruction-following, and overall efficiency. Built on a hybrid SSM-Transformer architecture with a 256K context...
Full AI21: Jamba Large 1.7 specs →Claude Opus 5 (Fast)
Fast-mode variant of [Opus 5](/anthropic/claude-opus-5) - identical capabilities with higher output speed at 2x pricing relative to regular Opus 5. Learn more in Anthropic's docs: https://platform.claude.com/docs/en/build-with-claude/fast-mode
Full Claude Opus 5 (Fast) specs →