Cost per coding-agent request

Is Claude Sonnet 4.6 or GPT-5.6 Terra cheaper for coding agents?

For coding agents, Claude Sonnet 4.6 costs 1.2x as much as GPT-5.6 Terra per request ($0.097 vs $0.084 on our measured traffic), because Claude Sonnet 4.6 lists at $3 input, $0.30 cached input and $15 output per million tokens against $2, $0.20 and $12 for GPT-5.6 Terra, and GPT-5.6 Terra charges more for prompts over 272K tokens.

List prices: Anthropic pricing, OpenAI API pricing, checked 2026-10-13. Request costs: Standard Compute gateway data, 79,301 coding-agent requests from 75 users, Sep 13 to Oct 12, 2026. How we compute this

Run GPT-5.6 Terra and Claude Sonnet 5.5 in your agent from $19/month

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Cost per coding-agent request, side by side

Cost at list price	GPT-5.6 Terra	Sonnet 4.6
Prompt under 100K tokens50% of requests, 87% of input cached	$0.032	$0.047
Prompt of 100K to 272K39% of requests, 88% of input cached	$0.080	$0.12
Prompt over 272K tokens11% of requests, 86% of input cached	$0.34	$0.26
Average request	$0.084	$0.097
100 requests	$8.40	$9.74
Median session16 requests; a session ends after 10 idle minutes	$0.92	$1.35
A month of regular usemedian of 20 users active on 5+ days	$118	$149

Each logged request priced at the vendor’s list rates for its own token counts, including cache reads and any higher rate for long prompts. Average output: 698 tokens per request.

Benchmarks, speed and latency, side by side

Artificial Analysis	GPT-5.6 Terra	Sonnet 4.6
Intelligence Index10 evaluations, 0 to 100	42	30
Terminal-Bench 4.0agentic coding in a terminal	35.4%	3.0%
Output speedmedian	135 tokens/s	57 tokens/s
Time to first answer tokenincludes thinking time	2.2 min	101 s

Source: Artificial Analysis (artificialanalysis.ai). Measured variants: GPT-5.6 Terra (Max), speed on OpenAI; Claude Sonnet 4.6 (Max), speed on Anthropic. Fetched October 13, 2026. Artificial Analysis runs Terminal-Bench 4.0 in its own setup, so its scores differ from the tbench.ai leaderboard.

What to watch for

Claude Sonnet 4.6 is superseded: Claude Sonnet 5.5 costs $0.053 per request. GPT-5.6 Terra scores as well or better on the benchmarks above, so the cheaper request is not bought with much lower ability.

FAQ

Is GPT-5.6 Terra cheaper than Claude Sonnet 4.6 for coding agents?

Yes, at list prices. 100 average coding-agent requests cost $8.40 on GPT-5.6 Terra and $9.74 on Claude Sonnet 4.6. A median 16-request session costs $0.92 vs $1.35. Measured on 79,301 real coding-agent requests (Sep 13 to Oct 12, 2026).

How much does a month of Sonnet 4.6 vs GPT-5.6 Terra cost?

For the median regular user in our data (1,478 requests in 30 days), about $149 on Claude Sonnet 4.6 and $118 on GPT-5.6 Terra at list price. Heavier users pay proportionally more.

Claude Sonnet 4.6 vs GPT-5.6 Terra: which is better for agents?

GPT-5.6 Terra scores higher on output quality (8.0/10 vs 6.4/10), while GPT-5.6 Terra is the cheaper option. Claude Sonnet 4.6 is best for existing Sonnet 4.6 setups until they move to Sonnet 5.5; GPT-5.6 Terra is best for fast mid-tier work in existing GPT-5.6 setups. Live community votes on this page show what people actually prefer.

Can I switch between Claude Sonnet 4.6 and GPT-5.6 Terra in the same agent?

Yes. Model-agnostic agents (Cline, Aider, OpenClaw, Hermes Agent, Kilo Code, OpenCode) let you swap models per task. Many people route hard tasks to the stronger model and routine work to the cheaper one.

Community vote

Pick a winner in each dimension. You can change your vote any time.

Output Quality

Correctness and depth of what it produces

Agentic Ability

Tool calls, instruction-following, and multi-step tasks

Speed

Tokens per second and time-to-first-token

Value for Money

How much capability you get per dollar

Reliability

Consistent results: fewer refusals, loops and format breaks

Current Claude, GPT, Gemini and open models are included with Standard Compute

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Current frontier models Claude Fable 5.1 · GPT-6 Astra

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