Claude Opus 4.1 (2025-08-05) vs Claude Opus 4.6 (2026-02-05)

Claude Opus 4.1 (2025-08-05) (Anthropic, 200,000-token context) versus Claude Opus 4.6 (2026-02-05) (Anthropic, 1,000,000-token context). Claude Opus 4.6 (2026-02-05) is cheaper by 67% on a blended token mix. Across 1 public benchmark we tracked, Claude Opus 4.1 (2025-08-05) wins 0 and Claude Opus 4.6 (2026-02-05) wins 1. Use the live calculator below to plug your real usage shape into both, then route the winner via Agent Command Center for shadow A/B without code changes.

Bottom line — Claude Opus 4.1 (2025-08-05) vs Claude Opus 4.6 (2026-02-05)

Claude Opus 4.1 (2025-08-05) and Claude Opus 4.6 (2026-02-05) target overlapping workloads but differ sharply on economics. Claude Opus 4.6 (2026-02-05) runs roughly 67% cheaper on a blended input-plus-output token mix, which translates to approximately $60,000 per month at mid-market volume (100K requests/day). The gap compounds at enterprise scale, making the cost axis the first filter most teams apply when deciding between these two models.

Claude Opus 4.6 (2026-02-05) ships a 1,000,000-token context window, 5.0x larger than Claude Opus 4.1 (2025-08-05)'s 200,000 tokens. That headroom matters for long-document RAG pipelines, multi-turn agent sessions that accumulate tool-call history, and codebases where the entire repository needs to fit in a single prompt. If your average prompt stays under 200,000 tokens, the extra context on Claude Opus 4.6 (2026-02-05) is insurance you may never use — and Claude Opus 4.1 (2025-08-05) may win on other axes.

For teams evaluating both models, the recommended path is a shadow A/B test: route production traffic through an OpenAI-compatible gateway, mirror a percentage to the candidate model, score both responses with an automated evaluator (faithfulness, tool-call correctness, latency), and compare cohort-level metrics over two weeks. Future AGI Agent Command Center supports this pattern with a single `base_url` change and built-in evaluators from the ai-evaluation SDK.

Side-by-side cost

Live workload comparison

Same workload run through both models. The cheaper one is highlighted.

3,000
01,000,000
400
0128,000
5,000
01,000,000
Anthropic
$11,414/mo
Input $15.00/M · Output $75.00/M
Anthropic
$3,805/mo
Input $5.00/M · Output $25.00/M
At this workload, Claude Opus 4.6 (2026-02-05) is 67% cheaper than Claude Opus 4.1 (2025-08-05) — a savings of $7,609/month ($91,313/year).
Production recipe — Agent Command Center
strategy: cost-optimized
primary:
  model: claude-opus-4-6-20260205
  provider: anthropic
fallback:
  model: claude-opus-4-1-20250805
  provider: anthropic
shadow: { sample_rate: 0.05 }   # mirror 5% of traffic to compare quality live
Claude Opus 4.1 (2025-08-05) Claude Opus 4.6 (2026-02-05)
Input price $15.00/M $5.00/M
Output price $75.00/M $25.00/M
Context window 200,000 1,000,000
Max output 32,000 128,000
Function calling
Vision
Audio input
Reasoning
Prompt caching
Structured output
Pricing verified Jun 2, 2026 Jun 2, 2026
Cheaper option
~67% cheaper than the priciest in this pair
Larger context
1,000,000 tokens
More capabilities
5 of 6 capability flags advertised

Benchmark comparison

Side-by-side public benchmark scores. Greener bar = winner.

Chatbot Arena ELOgeneral
Claude Opus 4.1 (2025-08-05)
1,447
Claude Opus 4.6 (2026-02-05)
1,498
HumanEvalcode
Claude Opus 4.1 (2025-08-05)
92.4%
Claude Opus 4.6 (2026-02-05)
IFEvalgeneral
Claude Opus 4.1 (2025-08-05)
89.1%
Claude Opus 4.6 (2026-02-05)
MMLU-Proreasoning
Claude Opus 4.1 (2025-08-05)
87.0%
Claude Opus 4.6 (2026-02-05)
BFCL v3agent
Claude Opus 4.1 (2025-08-05)
86.3%
Claude Opus 4.6 (2026-02-05)
GPQA Diamondreasoning
Claude Opus 4.1 (2025-08-05)
79.6%
Claude Opus 4.6 (2026-02-05)
MMMUmultimodal
Claude Opus 4.1 (2025-08-05)
79.1%
Claude Opus 4.6 (2026-02-05)
SWE-bench Verifiedagent
Claude Opus 4.1 (2025-08-05)
74.5%
Claude Opus 4.6 (2026-02-05)

Cost at scale: monthly spend at three usage volumes

Estimated monthly cost assuming 1,000 input + 200 output tokens per request — a realistic chat-agent shape. Adjust your own usage in the calculator at the top of this page for an exact number.

Scale Claude Opus 4.1 (2025-08-05) Claude Opus 4.6 (2026-02-05) Delta
Startup
10K requests/day
$9,000 /mo $3,000 /mo $6,000/mo
Mid-market
100K requests/day
$90,000 /mo $30,000 /mo $60,000/mo
Enterprise
1M requests/day
$900,000 /mo $300,000 /mo $600,000/mo

At enterprise scale (1M requests/day), a difference of even ~10% in unit price compounds into thousands of dollars per month. Cached input pricing and batch tiers can shift this further — both are surfaced on each model's own page.

When to choose which

Picked from the data above — not vendor marketing. Match the rules to your workload, not the other way around.

Choose Claude Opus 4.6 (2026-02-05)

You're cost-sensitive at scale — Claude Opus 4.6 (2026-02-05) runs ~67% cheaper on a blended in+out token mix, compounding into thousands of dollars per month at production volume.

Choose Claude Opus 4.6 (2026-02-05)

Your workload needs long context — Claude Opus 4.6 (2026-02-05) fits 1,000,000 tokens versus the other model's 200,000, enough headroom for full books, large codebases, or 100+ page documents in one shot.

Choose Claude Opus 4.6 (2026-02-05)

On arena-elo, Claude Opus 4.6 (2026-02-05) scores 51.0 points higher — if your workload pattern matches that benchmark's task shape, the gap is meaningful.

Benchmark winners — by the numbers

For each public benchmark that has scores for both models, the higher score and the size of the gap. Benchmarks are noisy — treat anything under a 2-point delta as effectively tied.

Benchmark Claude Opus 4.1 (2025-08-05) Claude Opus 4.6 (2026-02-05) Winner Δ
arena-elo 1447.0 1498.0 Claude Opus 4.6 (2026-02-05) +51.0

Migration considerations

Concrete differences to wire through your stack before you flip traffic from one to the other.

  • Context window changes up 400% when moving from Claude Opus 4.1 (2025-08-05) (200,000) to Claude Opus 4.6 (2026-02-05) (1,000,000). Re-check any prompt that relies on cramming long history or documents.
  • Max output tokens differ: 32,000 on Claude Opus 4.1 (2025-08-05) vs 128,000 on Claude Opus 4.6 (2026-02-05). Long-form generation tasks may truncate differently — adjust streaming UI and chunking accordingly.

How to A/B test Claude Opus 4.1 (2025-08-05) vs Claude Opus 4.6 (2026-02-05) in production

If you're stuck between the two, run them side-by-side on real traffic. Four steps the Future AGI team uses internally:

  1. 1. Point your existing OpenAI SDK at https://gateway.futureagi.com/v1. No code change beyond base_url and a virtual key.
  2. 2. Mark Claude Opus 4.1 (2025-08-05) primary, mirror 20% of traffic to Claude Opus 4.6 (2026-02-05) in shadow mode. Both responses are logged; only the primary is served to users.
  3. 3. Score every shadow response with an evaluator — faithfulness, tool-call correctness, response latency, cost. Built-in evaluators in ai-evaluation cover the common axes.
  4. 4. Compare cohort-level metrics after two weeks. Switch primary when the candidate wins on what matters to your workload — and stays within your latency budget.

Full walkthrough on the Agent Command Center page.

FAQ — Claude Opus 4.1 (2025-08-05) vs Claude Opus 4.6 (2026-02-05)

Which is cheaper, Claude Opus 4.1 (2025-08-05) or Claude Opus 4.6 (2026-02-05)?

Claude Opus 4.6 (2026-02-05) is cheaper by roughly 67% on a blended input + output token mix. Input prices are $15.00/M for Claude Opus 4.1 (2025-08-05) versus $5.00/M for Claude Opus 4.6 (2026-02-05); output prices are $75.00/M versus $25.00/M. The exact savings depend on your input:output ratio — use the live calculator above to plug in your own request shape.

What is the context window of Claude Opus 4.1 (2025-08-05) versus Claude Opus 4.6 (2026-02-05)?

Claude Opus 4.1 (2025-08-05) supports up to 200,000 tokens of context. Claude Opus 4.6 (2026-02-05) supports up to 1,000,000 tokens. Claude Opus 4.6 (2026-02-05) has the larger window by a factor of 5.0x, which matters for long-document RAG, multi-turn agent sessions, and tasks that need to keep an entire codebase in working memory.

Do Claude Opus 4.1 (2025-08-05) and Claude Opus 4.6 (2026-02-05) both support tool calling?

Yes — both Claude Opus 4.1 (2025-08-05) and Claude Opus 4.6 (2026-02-05) support native function calling. Both also support structured output via JSON schema, so an agent can be ported between them with the same tool definitions.

Which model supports prompt caching for cost reduction?

Both Claude Opus 4.1 (2025-08-05) and Claude Opus 4.6 (2026-02-05) support prompt caching. Cached input tokens are typically discounted 50–90% versus uncached input, depending on the provider. For agents with a stable system prompt + retrieval context, the cached pricing tier is the real unit economics number to track.

When should I choose Claude Opus 4.1 (2025-08-05) over Claude Opus 4.6 (2026-02-05)?

On the data this page surfaces, Claude Opus 4.1 (2025-08-05) is the right pick when Claude Opus 4.6 (2026-02-05)'s lower price or different capability profile aren't a fit for your workload. Run the live calculator above against your actual usage shape to confirm.

When should I choose Claude Opus 4.6 (2026-02-05) over Claude Opus 4.1 (2025-08-05)?

You're cost-sensitive at scale — Claude Opus 4.6 (2026-02-05) runs ~67% cheaper on a blended in+out token mix, compounding into thousands of dollars per month at production volume. Your workload needs long context — Claude Opus 4.6 (2026-02-05) fits 1,000,000 tokens versus the other model's 200,000, enough headroom for full books, large codebases, or 100+ page documents in one shot. On arena-elo, Claude Opus 4.6 (2026-02-05) scores 51.0 points higher — if your workload pattern matches that benchmark's task shape, the gap is meaningful.

How do I A/B test Claude Opus 4.1 (2025-08-05) against Claude Opus 4.6 (2026-02-05) in production?

Route both through an OpenAI-compatible gateway like Future AGI Agent Command Center with shadow mode enabled. Send 100% of traffic to your primary model, mirror 10–20% to the candidate, score every response with an evaluator (faithfulness, tool-call correctness, response time), and compare cohort-level metrics for two weeks. Switch when the candidate wins on the metrics that matter to your workload and stays within your latency budget.