GPT-5.6 Terra vs DeepSeek V4-Pro
OpenAI's GPT-5.6 Terra and DeepSeek's DeepSeek V4-Pro both target production language workloads, but they price and behave differently. Here is the side-by-side.
Pricing checked against provider documentation on . How we verify
The short answer
DeepSeek V4-Pro is the cheaper option — roughly 4.5x less on a blended workload, and it suits frontier-adjacent reasoning at open-weight prices. GPT-5.6 Terra justifies its premium when you need balanced production workloads.
OpenAI • GPT-5.6
$2.00 / $12.00
/ 1M tokens (input / output)
The everyday tier of the GPT-5.6 family, roughly corresponding to the old 'mini' slot but benchmarking above the previous generation's flagship. For most application backends this is the default worth trying before reaching for Sol, since it clears Claude Fable 5 on several evals at a fraction of the cost.
DeepSeek • DeepSeek V4
$0.66 / $1.98
/ 1M tokens (input / output)
A 1.6T-parameter mixture-of-experts model with 49B active, released under MIT and callable through DeepSeek's own API with configurable reasoning effort. Since 16 August 2026 DeepSeek bills on a peak/off-peak schedule, so the hour you run a job changes the bill by exactly 2x — which makes it unusually well suited to scheduled batch work.
Input price
DeepSeek V4-Pro is 67% cheaper than GPT-5.6 Terra on input tokens.
Output price
DeepSeek V4-Pro is 84% cheaper than GPT-5.6 Terra on output tokens — usually the side that dominates the bill.
Monthly cost at three workload sizes
Standard (non-batch, non-cached) rates. Reasoning models will exceed these figures because thinking tokens bill as output.
| Workload | GPT-5.6 Terra | DeepSeek V4-Pro | Difference |
|---|---|---|---|
| Light — 1M in / 200K out | $4 | $1 | $3 |
| Moderate — 10M in / 2M out | $44 | $11 | $33 |
| Heavy — 100M in / 20M out | $440 | $106 | $334 |
Specification comparison
| Attribute | GPT-5.6 Terra | DeepSeek V4-Pro |
|---|---|---|
| Input (/ 1M tokens) | $2.00 | $0.66 |
| Output (/ 1M tokens) | $12.00 | $1.98 |
| Cached input | $0.20 | $0.02 |
| Context window | 1,048,576 tokens | 1,000,000 tokens |
| Max output | 128,000 tokens | 131,072 tokens |
| Native reasoning | Yes | Yes |
| Knowledge cutoff | 2026-02 | 2026-03 |
| Relative latency | medium | medium |
| Open weights | No | MIT |
| API model ID | gpt-5.6-terra | deepseek-v4-pro |
| Status | stable | stable |
GPT-5.6 Terra: Cut 20% from the $2.50/$15 launch price on 2026-07-30.
DeepSeek V4-Pro: Off-peak rate shown. Peak rates are exactly double ($1.32 input / $3.96 output) during 01:00–04:00 and 06:00–10:00 UTC, Monday to Friday. Cache hits cost roughly 3% of a cache miss.
Choose GPT-5.6 Terra if…
- Customer support and chat backends
- RAG and document processing pipelines
- Mid-complexity coding tasks
- Tool-calling agents at scale
Choose DeepSeek V4-Pro if…
- Overnight batch reasoning jobs
- Self-hosted deployments needing MIT terms
- Cost-sensitive coding agents
- Chinese-language workloads
Frequently asked
Is GPT-5.6 Terra or DeepSeek V4-Pro cheaper?
DeepSeek V4-Pro is cheaper. On a blended 3:1 input-to-output workload it costs about 4.5x less than GPT-5.6 Terra.
Which has the larger context window, GPT-5.6 Terra or DeepSeek V4-Pro?
GPT-5.6 Terra has the larger window at 1.05M tokens versus 1M.
Should I use GPT-5.6 Terra or DeepSeek V4-Pro?
Pick GPT-5.6 Terra for balanced production workloads. Pick DeepSeek V4-Pro for frontier-adjacent reasoning at open-weight prices. If cost dominates the decision, DeepSeek V4-Pro wins; if you need the capability ceiling, benchmark both on your own evals before committing.