For coding agents, GPT-5.6 Terra costs 13x as much as DeepSeek V4 Flash per request ($0.084 vs $0.0067 on our measured traffic), because GPT-5.6 Terra lists at $2 input, $0.20 cached input and $12 output per million tokens against $0.30, $0.006 and $1.20 for DeepSeek V4 Flash, and GPT-5.6 Terra charges more for prompts over 272K tokens.
Run any of these models in your agent from $19/month
See plans| Cost at list price | DeepSeek V4 Flash | GPT-5.6 Terra |
|---|---|---|
| Prompt under 100K tokens50% of requests, 87% of input cached | $0.0033 | $0.032 |
| Prompt of 100K to 272K39% of requests, 88% of input cached | $0.0080 | $0.080 |
| Prompt over 272K tokens11% of requests, 86% of input cached | $0.018 | $0.34 |
| Average request | $0.0067 | $0.084 |
| 100 requests | $0.67 | $8.40 |
| Median session16 requests; a session ends after 10 idle minutes | $0.091 | $0.92 |
| A month of regular usemedian of 20 users active on 5+ days | $9.13 | $118 |
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.
| Artificial Analysis | DeepSeek V4 Flash | GPT-5.6 Terra |
|---|---|---|
| Intelligence Index10 evaluations, 0 to 100 | 39 | 42 |
| Terminal-Bench 4.0agentic coding in a terminal | 26.8% | 35.4% |
| Output speedmedian | 195 tokens/s | 135 tokens/s |
| Time to first answer tokenincludes thinking time | 11 s | 2.2 min |
Source: Artificial Analysis (artificialanalysis.ai). Measured variants: DeepSeek V4.1 Flash (Max), speed on DeepSeek; GPT-5.6 Terra (Max), speed on OpenAI. Fetched October 13, 2026. Artificial Analysis runs Terminal-Bench 4.0 in its own setup, so its scores differ from the tbench.ai leaderboard.
The gap widens on long prompts: under 100K tokens GPT-5.6 Terra costs 9.9x as much per request, over 272K 19x. 87% of agent input is read from cache, and GPT-5.6 Terra charges $0.20 per million for it against $0.006. DeepSeek V4 Flash is superseded: DeepSeek V4.1 Flash costs $0.0067 per request.
Pick a winner in each dimension. You can change your vote any time. 10 votes cast so far.
Correctness and depth of what it produces
Tool calls, instruction-following, and multi-step tasks
Tokens per second and time-to-first-token
How much capability you get per dollar
Consistent results: fewer refusals, loops and format breaks
Setting it up? GPT-5.6 Terra: model ID, providers and agent config
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Every model on this page is included with Standard Compute