Claude Sonnet 5 vs GPT-5.6 Sol
GPT-5.6 Sol and Claude Sonnet 5 answer different buyer questions after OpenAI's July 2026 GA launch. Sol is OpenAI's maximum-capability frontier route with 1.05M context, max reasoning effort, and refreshed launch-table agent rows. Sonnet 5 is Anthropic's balanced Claude workhorse for day-to-day coding and workflow automation at lower token cost than Fable 5.
Pick GPT-5.6 Sol when you need OpenAI's newest GA frontier tier, Codex integration, and the deepest July 2026 launch evidence for coding agents and multimodal work. Pick Claude Sonnet 5 when Anthropic behavior, broad cloud partner availability, and Sonnet-tier economics fit the workload better than maximum frontier capability. Do not reuse Claude Fable 5 benchmark rows for Sonnet 5.
Decision scorecard
Local evidence first| Signal | Claude Sonnet 5 | GPT-5.6 Sol |
|---|---|---|
| Best for | reasoning-heavy apps, multimodal apps, and tool-calling agents | reasoning-heavy apps, multimodal apps, and tool-calling agents |
| Decision fit | Coding, RAG, and Agents | Coding, RAG, and Agents |
| Context window | 1m | 1.05m |
| Cheapest output | $10/1M tokens | $30/1M tokens |
| Provider routes | 5 tracked | 2 tracked |
| Shared benchmarks | 4 shared | SWE-bench Pro leader |
Decision tradeoffs
- Claude Sonnet 5 has the lower cheapest tracked output price at $10/1M tokens.
- Claude Sonnet 5 has broader tracked provider coverage for fallback and procurement flexibility.
- Claude Sonnet 5 uniquely exposes Structured outputs in local model data.
- Local decision data tags Claude Sonnet 5 for Coding, RAG, and Agents.
- GPT-5.6 Sol holds a shared-benchmark lead on SWE-bench Pro, ahead by 1.4 points.
- GPT-5.6 Sol has the larger context window for long prompts, retrieval packs, or transcript analysis.
- Local decision data tags GPT-5.6 Sol for Coding, RAG, and Agents.
Monthly cost at traffic
Estimate token spend from the cheapest tracked input and output route or tier on this page.
Claude Sonnet 5
$4,100
Cheapest tracked route/tier: OpenRouter
GPT-5.6 Sol
$11,500
Cheapest tracked route/tier: OpenAI API 0-272K input tokens
Estimated monthly gap: $7,400. Batch, cache, alternate speed tiers, and negotiated pricing are excluded from this local estimate.
Switch friction
- Provider overlap exists on OpenRouter; start route-level A/B tests there.
- GPT-5.6 Sol is $20/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
- Check replacement coverage for Structured outputs before moving production traffic.
- Provider overlap exists on OpenRouter; start route-level A/B tests there.
- Claude Sonnet 5 is $20/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
- Claude Sonnet 5 adds Structured outputs in local capability data.
Specs
| Specification | ||
|---|---|---|
| Released | 2026-06-30 | 2026-07-09 |
| Context window | 1m | 1.05m |
| Parameters | — | — |
| Architecture | Decoder Only | Decoder Only |
| License | Proprietary | Proprietary |
| Openness | Proprietary | Proprietary |
| Weights | Not released | Not released |
| Code | Unknown | Unknown |
| Commercial use | Commercial use: conditional | Commercial use: conditional |
| Knowledge cutoff | 2026-01 | - |
Pricing and availability
| Pricing attribute | Claude Sonnet 5 | GPT-5.6 Sol |
|---|---|---|
| Input price | $2/1M tokens |
|
| Output price | $10/1M tokens |
|
| Providers |
Capabilities
| Capability | Claude Sonnet 5 | GPT-5.6 Sol |
|---|---|---|
| Vision | Yes | Yes |
| Multimodal | Yes | Yes |
| Reasoning | Yes | Yes |
| Function calling | Yes | Yes |
| Tool use | Yes | Yes |
| Structured outputs | Yes | No |
| Code execution | Yes | Yes |
| IDE integration | No | No |
| Computer use | No | No |
| Parallel agents | No | No |
Benchmarks
| Benchmark | Claude Sonnet 5 | GPT-5.6 Sol |
|---|---|---|
| SWE-bench Pro | 63.2 | 64.6 |
| Terminal-Bench 2.1 | 80.4 | 88.8 |
| BrowseComp | 84.7 | 90.4 |
| BrowseComp — Multi-Agent | 86.6 | 92.2 |
Deep dive
This is a flagship-versus-workhorse comparison, not Anthropic's top-tier matchup. Sonnet 5 is the practical Claude default; Claude Fable 5 is the higher-tier Anthropic anchor for maximum capability claims.
GPT-5.6 Sol should lead on July 2026 OpenAI GA rows such as DeepSWE 1.1, BrowseComp, OSWorld 2.0, and GPQA Diamond from launch materials. Sonnet 5 should use Sonnet-specific Anthropic or independent rows only.
Pricing and context differ by workload shape. GPT-5.6 Sol lists $5/$30 up to 272K input tokens with a long-context surcharge above that threshold and a 1.05M context window. Sonnet 5 is the lower-cost Claude route for teams that do not need Fable 5 pricing or refusal complexity.
Provider fit matters as much as benchmark deltas. Sol is the OpenAI-native path across ChatGPT, Codex, and the API. Sonnet 5 is widely available through Claude API, Bedrock, Vertex AI, and Microsoft Foundry for Anthropic-first teams.
FAQ
Which model is better for everyday production use?
Claude Sonnet 5 is the practical Anthropic workhorse for balanced coding and workflow automation. GPT-5.6 Sol is the stronger pick when you need OpenAI's newest GA frontier capability and are willing to revalidate prompts on the July 2026 Sol route.
Is Sonnet 5 the same tier as Claude Fable 5?
No. Sonnet 5 is Anthropic's balanced Sonnet-tier model. Claude Fable 5 is the higher Mythos-class tier with different pricing, refusal behavior, and benchmark evidence. Do not borrow Fable 5 scores for Sonnet 5.
Which model has better coding-agent evidence?
Use source-labeled rows only. GPT-5.6 Sol has July 2026 OpenAI GA launch rows for agentic coding and tool use. Sonnet 5 should be evaluated on Sonnet-specific Anthropic or independent benchmark rows, not Fable 5 claims.
Which model is cheaper?
Compare your real prompt length and provider route. Sonnet 5 is generally the lower-cost Claude tier versus Fable 5. GPT-5.6 Sol and GPT-5.5 share similar short-context OpenAI pricing patterns, so the decision should combine token economics with capability fit.
Continue comparing
Last reviewed: 2026-07-09. Data sourced from public model cards and provider documentation.