GPT-5.6 Terra vs Kimi K3.1 Pro.
Verdict by category, tale of the tape, shared benchmarks only, and cost at three workloads — all from the tracked data.
Verdict by category
| Category | GPT-5.6 Terra | Kimi K3.1 Pro | Winner |
|---|---|---|---|
| League Score | 68.6 | 69.4 | Kimi K3.1 Pro |
| Coding (SWE-bench %) | — | — | — |
| Reasoning (GPQA %) | 92.9 | — | — |
| Context (tokens) | 1050000 | 1048576 | GPT-5.6 Terra |
| Speed (tok/s) | — | — | — |
| Price (blended $/1M) | $4.50 | $4.00 | Kimi K3.1 Pro (cheaper) |
Tale of the tape
| Spec | GPT-5.6 Terra | Kimi K3.1 Pro |
|---|---|---|
| Maker | OpenAI | Moonshot AI |
| Released | Jul 9, 2026 | Oct 23, 2026 |
| League Score | 69 | 69 |
| Context | 1,050,000 tokens | 1,048,576 tokens |
| Max output | 128,000 | 131,072 |
| $/1M input | $2.00 | $2.00 |
| $/1M output | $12.00 | $10.00 |
| Weights | Closed | Open |
| Speed | — | — |
Head-to-head benchmarks (shared only)
| Benchmark | GPT-5.6 Terra | Kimi K3.1 Pro |
|---|---|---|
| LiveBench overall | 67.8 | 71.3 |
Cost at three workloads
| Workload | GPT-5.6 Terra | Kimi K3.1 Pro |
|---|---|---|
| Light — 1M in / 250K out | $5.00 | $4.50 |
| Standard — 10M in / 2.5M out | $50.00 | $45.00 |
| Long-context — 50M in / 5M out | $160.00 | $150.00 |
The pick
Pick GPT-5.6 Terra if you need the bigger context window.
Pick Kimi K3.1 Pro if you want the higher overall League Score; you want the lower running cost; you want downloadable weights / self-hosting.
All figures from the model database — sources and dates on each model page. Cost your own workload or compare a different pair.
Frequently asked questions
Which is better overall, GPT-5.6 Terra or Kimi K3.1 Pro?
On overall League Score they are effectively tied — GPT-5.6 Terra scores 69 and Kimi K3.1 Pro scores 69. The category verdicts on this page are where the real differences live.
Which is cheaper, GPT-5.6 Terra or Kimi K3.1 Pro?
Kimi K3.1 Pro is cheaper: $4.00 vs $4.50 blended per 1M tokens (3:1 input/output mix) — about 1.1x less per token.
Which has the bigger context window, GPT-5.6 Terra or Kimi K3.1 Pro?
GPT-5.6 Terra, with 1.1M of context against 1M for Kimi K3.1 Pro.
Are GPT-5.6 Terra and Kimi K3.1 Pro open source?
GPT-5.6 Terra is closed weights — API access only; Kimi K3.1 Pro is open weights — it can be downloaded and self-hosted.