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Claude Opus 5 vs GPT-5.6 Sol: API speed, coding and cost

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GPT-5.6 Sol starts answering sooner, while Claude Opus 5 streams output faster and recorded fewer server errors across traffic routed through us. For API developers, that makes the initial wait and handling failures central to the choice. Sol’s lower headline prices also become a much smaller advantage after caching.

The short answer

Verdict

Choose GPT-5.6 Sol for interactive API features where a short wait before the first token matters most. Choose Claude Opus 5 for automated coding jobs where fewer server failures and faster output streaming take priority. Across traffic routed through us, caching left only a small blended-cost difference.

At a glance

GPT-5.6 Sol offers slightly more room for long prompts, while Claude Opus 5 has computer-use support available through our endpoints. In our catalog, Sol has a 1.05-million-token context window versus Opus 5’s 1 million. Both cap output at 128,000 tokens, so Sol’s extra capacity accommodates more source material rather than a longer generated response.

Intelligence
Claude Opus 550.7
GPT-5.6 Sol47.1
Artificial Analysis Intelligence Index
Coding
Claude Opus 578
GPT-5.6 Sol77.4
Artificial Analysis Coding Index
Context
Claude Opus 51,000K
GPT-5.6 Sol1,050K
Widest context window any provider serves
Time to first token
Claude Opus 51,714 ms
GPT-5.6 Sol593 ms
Median across all Requesty traffic
Output speed
Claude Opus 572 tok/s
GPT-5.6 Sol45 tok/s
Median across all Requesty traffic
Blended price
Claude Opus 5$1.8/M
GPT-5.6 Sol$1.71/M
Actual cost per million tokens across our routed customer traffic, after caching

At a glance

Claude Opus 5GPT-5.6 Sol
Trained byAnthropicOpenAI
Released2026-07-242026-07-09
Context window1M tokens1.05M tokens
Max output128K tokens128K tokens
Providers on Requestyanthropic, vertex, bedrockopenai, openai-responses, bedrock, azure
Image inputYesYes
Reasoning controlsYesYes
Prompt cachingYesYes
Tool callingYesYes
Computer useYesNo
Web searchYesYes
Structured outputYesYes
Open weightsNoNo
Data retention (first-party endpoint)30 days30 days
Trains on your dataNoNo
Share of Requesty tokens4.1%6.7%
Specifications and endpoint features from our catalog. Token share from our routed traffic.

Pricing and caching

Customers paid similar blended rates after caching across traffic routed through us from July 6 to September 7, 2026: $1.80 per million tokens for Opus 5 and $1.71 for Sol. Opus’s higher cache savings narrowed the list-price gap in our routed cost measurements.

Our headline endpoints list Sol at $4 per million input tokens and $20 per million output tokens, versus Opus at $5 and $25. Sol’s promotional rate applies to requests with at most 272,000 input tokens and is available through at least November 21, 2026, according to the OpenAI changelog and eligibility reporting.

Pricing and caching

Our routed customer traffic · 2026-07-06 to 2026-09-07

Requesty
MetricClaude Opus 5GPT-5.6 Sol
What customers paid
Blended price includes cache savings.
Blended price / 1M tokens$1.8$1.71
Cache hit rate87.7%79.9%
Bill saved by caching80%66.9%
Price breakdown and benchmark costs
MetricClaude Opus 5GPT-5.6 Sol
Customer traffic costs
Cost per request$0.062192$0.040726
Median session cost$0.15$1.28
List prices
Our catalog · 2026-09-09. Canonical endpoints: anthropic/claude-opus-5 / openai/gpt-5.6-sol.
Input / 1M tokens$5$4
Cached input / 1M tokens$0.5$0.4
Output / 1M tokens$25$20
Artificial Analysis cost per task
Weighted evaluation cost · Intelligence Index v4.3, 2026-09-09. Claude Opus 5 (Adaptive Reasoning, Max Effort) / GPT-5.6 Sol (max).
Cost per benchmark task$5.8584$1.9885
Endpoint list prices
All priced endpoints
USD per million tokens. Cached-input rates apply to eligible cache reads.
ModelEndpointInputOutputCached inputContext
Claude Opus 5anthropic$5.00$25.00$0.5001M
Claude Opus 5vertex$5.00$25.00$0.5001M
Claude Opus 5bedrock$5.00$25.00$0.5001M
Claude Opus 5vertex (us)$5.50$27.50$0.5501M
Claude Opus 5vertex (eu)$5.50$27.50$0.5501M
Claude Opus 5bedrock (eu-west-3)$5.50$27.50$0.5501M
Claude Opus 5bedrock (eu-central-1)$5.50$27.50$0.5501M
Claude Opus 5bedrock (eu-north-1)$5.50$27.50$0.5501M
Claude Opus 5bedrock (eu-west-1)$5.50$27.50$0.5501M
GPT-5.6 Solopenai$2.50$15.00$0.2501.1M
GPT-5.6 Solopenai-responses$2.50$15.00$0.2501.1M
GPT-5.6 Solopenai$4.00$20.00$0.4001.1M
GPT-5.6 Solbedrock (us-east-1)$4.40$22.00$0.4401.1M
GPT-5.6 Solbedrock (us-east-2)$4.40$22.00$0.4401.1M
GPT-5.6 Solopenai-responses$5.00$30.00$0.5001.1M
GPT-5.6 Solazure (eastus2)$5.00$30.00$0.5001.1M
GPT-5.6 Solazure (eastus2)$5.00$30.00$0.5001.1M
GPT-5.6 Solazure (swedencentral)$5.50$33.00$0.5501.1M
GPT-5.6 Solazure (swedencentral)$5.50$33.00$0.5501.1M

Benchmarks and use cases

The models are close on Artificial Analysis’s Coding Index, with a wider gap in Opus’s favor on the Intelligence and Agentic indices. The comparison uses Claude Opus 5 (Adaptive Reasoning, Max Effort) and GPT-5.6 Sol (max), with Intelligence Index version 4.3. Opus’s larger lead is in reasoning and agentic results rather than the coding index.

Benchmark scores

Artificial Analysis · source score units

Requesty
Claude Opus 5GPT-5.6 Sol
Intelligence IndexVersioned Artificial Analysis composite, not a percentage
50.7
47.1
Coding IndexArtificial Analysis coding composite for this snapshot
78
77.4
Agentic IndexArtificial Analysis agentic composite for this snapshot
56.2
50.5
Snapshot 2026-09-09. Claude Opus 5 (Adaptive Reasoning, Max Effort) / GPT-5.6 Sol (max). Index versions: 4.3 / 4.3.

Latency and throughput

Across traffic routed through us from July 6 to September 7, 2026, Sol had lower median and p95 time to first token. Opus generated output faster once streaming began, with higher median tokens per second. These describe different parts of the wait: when an answer starts appearing and how quickly the remaining text arrives.

Opus also recorded fewer server errors: a 0.1% 5xx rate versus Sol’s 6.8% in our routed traffic measurements. That is a substantial operational difference for jobs that must handle failed requests.

Latency and throughput

Our routed customer traffic · 2026-07-06 to 2026-09-07

Requesty
MetricClaude Opus 5GPT-5.6 Sol
Speed and errors
Median time to first token1,714 ms593 ms
p95 time to first token4,376 ms1,519 ms
Median output speed72 tok/s45 tok/s
Upstream 5xx error rate0.1%6.8%
Endpoint results
Claude Opus 5
EndpointFirst tokenOutput speedTotal
vertex (eu)1,808 msn/a7.8 s
bedrock (eu-central-1)1,809 msn/a7.4 s
bedrock (eu-west-3)1,911 msn/a8.5 s
bedrock (eu-west-1)2,161 msn/a10.1 s
bedrock (eu-north-1)2,337 msn/a10.8 s
bedrock2,342 ms86 tok/s4.9 s
vertex2,559 msn/a12.2 s
bedrock2,833 msn/a4.7 s
anthropic2,874 ms88 tok/s5.4 s
vertex (eu)3,882 ms79 tok/s6.6 s
vertex (us)4,128 ms165 tok/s5.5 s
vertex4,136 ms75 tok/s7.1 s
anthropic6,212 msn/a13.2 s
bedrock (eu-north-1)7,689 ms174 tok/s9.0 s
bedrock (eu-west-3)11,352 ms113 tok/s13.3 s
bedrock (eu-central-1)18,018 msn/a18.0 s
GPT-5.6 Sol
EndpointFirst tokenOutput speedTotal
bedrock (us-east-1)1,547 msn/a11.9 s
azure (swedencentral)1,688 msn/a9.3 s
openai1,941 ms78 tok/s4.8 s
azure (eastus2)3,745 msn/a17.3 s
openai7,496 msn/a11.2 s
openai11,548 ms79 tok/s14.3 s
azure (eastus2)18,919 ms86 tok/s21.5 s
openai-responses20,060 ms78 tok/s22.9 s
azure (swedencentral)22,357 ms70 tok/s25.5 s
azure (eastus2)23,167 ms75 tok/s26.0 s
openai-responses26,290 ms110 tok/s28.3 s
bedrock (us-east-2)28,333 ms119 tok/s30.2 s
bedrock (us-east-1)28,881 ms41 tok/s34.2 s

Posts on X

Here are some posts on X comparing both models.

Yuchen Jin
Yuchen Jin
@Yuchenj_UW · 2026-08-29
𝕏

I barely use Claude Opus 5 these days. It doesn’t talk like a normal person (especially in Chinese). Way too verbose and rarely to the point. GPT-5.6 Sol is better. Meanwhile, OSS models like GLM-5.3, GLM-5.3-Flash, and Kimi K3 are pretty good and cost-efficient. There’s no default winner anymore.

1.7K likes · 45 reposts · 133 repliesView post ↗
0xMarioNawfal
0xMarioNawfal
@RoundtableSpace · 2026-09-01
𝕏

Claude Opus 5 built a substantially better extreme-ocean project than GPT-5.6 Sol on the same prompt, spending almost 10x more while autonomously expanding and refining far beyond what was asked with no loop instruction. https://t.co/4ev08S7Gun

59 likes · 0 reposts · 8 repliesView post ↗
CoArena (YC S26)
CoArena (YC S26)
@coastyai · 2026-08-28
𝕏

Claude Opus 5 vs GPT-5.6 Sol for computer use. Build a self-contained one-screen HTML toy called TOAST LAUNCH and save it as toast-launch.html. Show a huge cheerful… GPT-5.6 Sol won against Claude Opus 5. Go try computer-use agents for free at https://t.co/j06lDMvOt2 https://t.co/adPh5xdAWQ

15 likes · 3 reposts · 4 repliesView post ↗
Andrew Liu
Andrew Liu
@andrew2liu · 2026-08-31
𝕏

As a side project, I asked GPT, Claude and Gemini to answer 2,800 user health questions and graded them with real doctor-written rubrics: https://t.co/IeAU1e6Rsg. Here's what I found: 1. GPT-5.6 Sol and Claude Opus 5 did best, getting 52-58% of information correct. https://t.co/S7mqRSwJ6E

8 likes · 1 reposts · 1 repliesView post ↗

Independent reviews

  • Across 50 identical one-shot prompts, Opus 5 and GPT-5.6 Sol had nearly equal average scores, with Sol tested at medium reasoning effort.Julian Goldie
  • GPT-5.6 Sol caught more known code-review issues; Opus 5 at x-high effort produced the cleanest actionable comment stream but had the lowest coverage.coderabbit.ai
  • In a same-prompt React Native habit-tracker build, final app quality was roughly tied; Opus 5 used more tokens because of simulator screenshot validation.youtube.com

How each model feels to use

Claude Opus 5

GPT-5.6 Sol

  • Some practitioners using GPT-5.6 Sol in Codex describe it as literal and predictable, taking fewer unrequested liberties in daily coding.news.ycombinator.com

Recent changes

  • As of August 28, 2026: Sol API pricing fell to $4 input and $20 output per million tokens for inputs up to 272,000 tokens, promotional through at least November 21, 2026.developers.openai.comtechnology.org

Which should you choose?

Choose GPT-5.6 Sol for daily coding and interactive features if you want quicker starts and more literal execution of your requests. Practitioners on Hacker News describe switching to Sol in Codex because it takes fewer unrequested liberties. If Claude’s wordiness makes routine exchanges harder to follow, that is a practical reason to try Sol.

Choose Claude Opus 5 for repository-level coding and novel reasoning, where DataCamp’s benchmark synthesis reports strengths. Keep task boundaries explicit: developer reports describe extra explanations and scope expansion that can make it more work to direct.

Our routed traffic measurements show Sol starts sooner, while Opus streams faster and recorded fewer 5xx errors. With coding index results close and blended rates similar after caching, prioritize the model whose working style suits the task.

Frequently asked questions
Which model fits more source code or documents?
GPT-5.6 Sol has a 1.05-million-token context window versus Opus 5’s 1 million in our catalog. Both cap generated output at 128,000 tokens.
How do cached-input prices compare?
The headline endpoints charge $0.40 per million cached-read tokens for Sol and $0.50 for Opus 5 in our catalog. Across our routed traffic, Opus’s higher cache savings narrowed the blended-cost gap.
Which model should I choose for code review?
Choose Sol when finding more known issues matters most. Choose Opus 5 at x-high effort when keeping review comments actionable matters more than coverage. CodeRabbit’s review found that trade-off in its tests.
How much does Claude Opus 5 cost?
The canonical endpoint lists Claude Opus 5 at $5 per million input tokens and $25 per million output tokens, with $0.50 per million cached-read tokens in our catalog. Across traffic routed through us, customers paid a $1.80 blended rate per million tokens after cache savings.
How much does GPT-5.6 Sol cost?
The canonical endpoint lists GPT-5.6 Sol at $4 per million input tokens and $20 per million output tokens, with $0.40 per million cached-read tokens in our catalog. The promotional rate applies to requests with at most 272,000 input tokens and is available through at least November 21, 2026. In our routed traffic the blended rate was $1.71 per million tokens after caching.
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