TL;DR: Claude and OpenAI no longer fit a simple “which flagship is cheaper” answer. Claude Sonnet 5 is the first Claude production test at $2/$10 per 1M tokens through August 31, then $3/$15. Opus 5 is the premium Claude baseline at $5/$25. OpenAI’s standard short-context GPT-5.6 family spans Luna at $0.20/$1.20, Terra at $2/$12, and Sol at $5/$30.
Anthropic says the June 12 export controls were lifted June 30 and Fable 5 returned globally on native Claude surfaces July 1. Included usage is temporary and plan-specific, cloud re-enablement is rolling out, and Mythos 5 remains restricted to approved organizations. Fable’s restored availability does not make it the default premium lane.
GPT-5.6 Sol, Terra, and Luna have been generally available since July 9. OpenAI cut Luna’s API price by 80% and Terra’s by 20% on July 30; Sol was unchanged. Product access is plan-dependent, while less-restricted cyber work uses Trusted Access. See the current model guide and Luna viability analysis.
Use this page for routing decisions, not rankings. Test before moving production workloads.
Current API Price Anchors
Prices are per 1 million tokens.
| Lane | Input | Cached input | Output | Batch input/output | Practical read |
|---|---|---|---|---|---|
| Claude Sonnet 5 | $2 intro; $3 standard | verify current cache rate | $10 intro; $15 standard | verify current pricing docs | Introductory pricing ends Aug 31 |
| Claude Opus 5 | $5 | $0.50 cache hits | $25 | $2.50 / $12.50 | Premium Claude baseline; tune effort |
| Claude Fable 5 | $10 | $1 cache hits | $50 | $5 / $25 | Restored guarded escalation; not a default lane |
| GPT-5.6 Sol, short context | $5 | $0.50 cache reads | $30 | $2.50 / $15 | Generally available flagship |
| GPT-5.6 Terra, short context | $2 | $0.20 cache reads | $12 | $1 / $6 | Generally available balanced tier |
| GPT-5.6 Luna, short context | $0.20 | $0.02 cache reads | $1.20 | $0.10 / $0.60 | Generally available high-volume tier |
| GPT-5.5 standard, short context | $5 | $0.50 | $30 | $2.50 / $15 | OpenAI-native premium lane |
| GPT-5.5 standard, long context | $10 | $1 | $45 | $5 / $22.50 | Long context when OpenAI fit matters |
| GPT-5.5 Pro, short context | $30 | not listed | $180 | $15 / $90 | Highest-cost OpenAI Pro lane |
GPT-5.6 model pages list a 1.05M context window. Requests above 272K input use long-context rates for the full request: Sol $10/$45, Terra $4/$18, and Luna $0.40/$1.80 input/output. Cache writes cost 1.25 times the applicable input rate.
Cost Sanity Check
For a 100K-input / 20K-output request:
| Model | Approx standard cost |
|---|---|
| Claude Sonnet 5 | $0.40 introductory / $0.60 standard |
| GPT-5.6 Luna standard short context | $0.044 |
| GPT-5.6 Terra standard short context | $0.44 |
| Claude Opus 5 | $1.00 |
| GPT-5.6 Sol standard short context | $1.10 |
| GPT-5.5 standard short context | $1.10 |
| GPT-5.5 standard long context | $1.90 |
| Claude Fable 5 | $2.00 |
| GPT-5.5 Pro short context | $6.60 |
Those numbers are only a starting point. Repeated-context workloads can favor OpenAI or Claude cache-hit pricing. Batch workloads halve both providers’ listed input and output token charges. Data residency, priority/fast modes, and tool/runtime charges can change the bill.
When Claude Wins
Choose Claude when:
- Sonnet 5 solves the task and you want Claude behavior at the lowest current Claude production price.
- Opus 5 improves architecture, debugging, review, or long-horizon agent work enough to justify $5/$25.
- You need Claude Code or claude.ai as the first-party workflow.
- You want to test Fable only after target-route access is confirmed, Opus misses a high-value task, and your data policy allows Fable’s retention terms.
Do not route sensitive workloads to Fable just because a benchmark or launch quote looks strong. Fable can refuse or fall back on guarded domains, and Anthropic documents 30-day retention with no zero-data-retention option for Fable/Mythos.
When OpenAI Wins
Choose the matching OpenAI tier when:
- Luna clears a bounded, high-volume task’s acceptance bar with controlled retries and review.
- Terra materially reduces Luna’s failure or cleanup rate.
- Sol changes the result on hard agentic, terminal, or final-review work.
- Cached input dominates the bill.
- OpenAI-native tooling, context, or API behavior fits better than Claude’s route.
GPT-5.5 standard short context is cheaper than Fable on both input and output. GPT-5.5 long context matches Fable input pricing and is cheaper on output. GPT-5.5 Pro is much more expensive than Fable, so use it only when the Pro behavior is measurably worth it.
Decision Matrix
| If your workload is… | Start with | Escalate to |
|---|---|---|
| Routine production coding | Claude Sonnet 5 or GPT-5.5 standard | Opus 5 if review/architecture quality matters |
| Premium Claude review | Opus 5 high | Raise effort after task-level measurement; use Fable only after access, compliance, and guardrail tests pass |
| OpenAI-native bounded volume | GPT-5.6 Luna | Terra when Luna’s retries or review erase the saving |
| OpenAI-native hard agentic work | GPT-5.6 Terra | Sol only when it changes the accepted result |
| Long-context repeated prompts | Compare cache-hit pricing on both providers | Batch or long-context lanes after a real bill estimate |
| Cyber, biology, chemistry, or model-development work | Guardrail test first | Trusted access or another approved model |
| Zero-data-retention requirement | Avoid Fable/Mythos-class routes | Use a model/contract that meets the requirement |
What To Test Before Buying
- Representative prompts from your real workload.
- Cost per successful task, not cost per token alone.
- Fallback/refusal logs for Fable-sensitive domains.
- Cache-hit rate on repeated context.
- Batch fit for asynchronous workloads.
- Data retention, data residency, and audit logging requirements.
- Tooling fit: Claude Code, Codex, cloud platform, or BYOK harness.
Sources
- Anthropic: Redeploying Fable 5 (Archive)
- Anthropic API docs: Claude Fable 5 and Claude Mythos 5 (Archive)
- Anthropic API docs: Pricing (Archive)
- Anthropic: Claude Sonnet 5 launch (Archive)
- Anthropic: Claude Opus 5 launch (Archive)
- Anthropic Platform: What’s new in Claude Opus 5 (Archive)
- Anthropic Platform: Sonnet 5 migration guide (Archive)
- OpenAI API docs: Pricing (Archive)
- OpenAI: July 30 GPT-5.6 price update (Archive)
- OpenAI: GPT-5.6 general availability
- Anthropic: Claude Fable 5 and Claude Mythos 5 (Archive)
- Anthropic: Statement on the US government directive to suspend access to Fable 5 and Mythos 5 (Archive)
- WIRED: Anthropic Says It’s Taking Claude Fable 5 Offline to Comply With US Government Order (Archive)
- The Verge: Anthropic cuts off Fable 5 and Mythos 5 access following government order (Archive)
- WIRED: Anthropic Is Still at Odds With the White House Over Claude Fable 5 (Archive) — June 15: talks unresolved
- The Verge: Trump’s Anthropic shutdown just made the case for non-American AI (Archive) — June 15: sovereign AI reaction
- Business Insider: An AI startup is suing the US government for taking away Anthropic’s new model (Archive) — June 24: reported Fable restoration behind nationality and onboarding controls
Related links
- /compare/models/premium/ — Fable, Opus, Sonnet, and GPT-5.5 decision ladder
- /posts/fable-5-returns-claude-sonnet-5/ — July 1 Fable restoration and Sonnet 5 default-lane analysis
- /posts/gpt-5-6-luna-price-cut/ — Luna benchmark synthesis and CAR decision
- /posts/claude-fable-5-mythos-5-cost-guardrails/ — Fable guardrails and buying test
- /value/smart-spend/ — Subscription and low-cost overflow strategy
- /models/claude-opus-4-5/ — Historical Opus 4.5 reference
Last updated: August 1, 2026. GPT-5.6 is generally available with separate short- and long-context rates; Opus 5 is the current premium Claude baseline; Fable 5 is restored and Mythos 5 remains restricted. Pricing, included usage, cloud availability, retention, and model terms can change independently.