Model comparison
GPT-5.6 Terra vs Laguna S 2.1
Head-to-head evidence from 4 shared benchmark results across 2 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.
Public leaderboard positions: GPT-5.6 Terra #11 (Estimated); Laguna S 2.1 unranked (Not scored). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.
Evidence parity. GPT-5.6 Terra and Laguna S 2.1 share 4 comparable benchmark results. 2 of 8 categories are comparable. 40 results are unique to GPT-5.6 Terra; 2 to Laguna S 2.1.
Updated July 21, 2026- Shared results
- 4
- GPT-5.6 Terra only
- 40
- Laguna S 2.1 only
- 2
- Comparable categories
- 2 / 8
Treat this as a split decision. GPT-5.6 Terra makes more sense if agentic is the priority; Laguna S 2.1 is the better fit if you want the cheaper token bill.
Confidence note. This is a partial-evidence comparison with 4 shared benchmark results across 2 evidence categories; 2 of 8 categories currently have scoreable aggregates for both models. Treat the verdict as directional until coverage is more balanced.
Why this result
GPT-5.6 Terra and Laguna S 2.1 finish on the same BenchAlign overall score, so this is less about a single winner and more about where the edge shows up. The BenchAlign headline says tie; the benchmark table is where the real choice happens.
GPT-5.6 Terra is also the more expensive model on tokens at $2.50 input / $15.00 output per 1M tokens, versus $0.10 input / $0.20 output per 1M tokens for Laguna S 2.1. That is roughly 75.0x on output cost alone.
Category breakdown
Exact category averages are shown below. Not measured means BenchLM does not have enough sourced public coverage for that model and category.
| Category | GPT-5.6 Terra | Δ | Laguna S 2.1 |
|---|---|---|---|
| Agentic | GPT-5.6 Terra87.4 | Margin← 17.2 | Laguna S 2.170.2 |
| Coding | GPT-5.6 Terra63.4 | Margin← 4.0 | Laguna S 2.159.4 |
| Knowledge | GPT-5.6 Terra92.9 | MarginNo overlap | Laguna S 2.1Not measured |
| Math | GPT-5.6 Terra80.8 | MarginNo overlap | Laguna S 2.1Not measured |
| Multimodal | GPT-5.6 Terra80.7 | MarginNo overlap | Laguna S 2.1Not measured |
Decisive benchmark drivers
The largest measured benchmark gaps in this matchup, with exact reported values.
More
- Source ↗
Terminal-Bench 2.0
AgenticA 87.4%B 70.2%Winner: GPT-5.6 TerraΔ 17.2Terminal-Bench 2.0: GPT-5.6 Terra scored 87.4%; Laguna S 2.1 scored 70.2%. GPT-5.6 Terra wins this benchmark. - Source ↗
SWE-bench Pro
CodingA 63.4%B 59.4%Winner: GPT-5.6 TerraΔ 4SWE-bench Pro: GPT-5.6 Terra scored 63.4%; Laguna S 2.1 scored 59.4%. GPT-5.6 Terra wins this benchmark.
Operational comparison
Runtime and commercial metrics are compared only when both models have a complete sourced value.
| Metric | GPT-5.6 Terra | Laguna S 2.1 | Comparison |
|---|---|---|---|
| Input / output priceUSD per 1M tokens | GPT-5.6 Terra$2.5 input / $15 output | Laguna S 2.1$0.1 input / $0.2 output | Laguna S 2.1 has the lower combined listed price. |
| Generation speedtokens per second | GPT-5.6 TerraNot available | Laguna S 2.1Not available | A complete speed comparison is not available. |
| First-answer latencyseconds to first token | GPT-5.6 TerraNot available | Laguna S 2.1Not available | A complete latency comparison is not available. |
| Context windowmaximum listed tokens | GPT-5.6 Terra1M | Laguna S 2.11M | Listed context windows are equal. |
Benchmark Deep Dive
AgenticGPT-5.6 Terra wins18 benchmarks
| Benchmark | GPT-5.6 Terra | Laguna S 2.1 | Result |
|---|---|---|---|
| Terminal-Bench 2.0Source | 87.4% | 70.2% | GPT-5.6 Terra leads |
| BrowseCompSource | 87.5% | — | Not comparable |
| OSWorld 2.0Source | 50.2% | — | Not comparable |
| CyberGymSource | 81.8% | — | Not comparable |
| ExploitGymSource | 23.2% | — | Not comparable |
| ToolathlonSource | 53.1% | — | Not comparable |
| AA Agentic IndexSource | 47.4% | — | Not comparable |
| τ²-bench resultsSource | 86.3% | — | Not comparable |
| GDPval-AASource | 54.1% | — | Not comparable |
| GDPval-AASource | 1581 | — | Not comparable |
| AA Harvey LABSource | 85.2% | — | Not comparable |
| AA ITBenchSource | 51.0% | — | Not comparable |
| AA Tau3 BankingSource | 31.8% | — | Not comparable |
| AA AutomationBenchSource | 45.6% | — | Not comparable |
| terminalBenchHardSource | 57.6% | — | Not comparable |
| aaTerminalBench21Source | 88% | — | Not comparable |
| APEX-Agents-AASource | 38.9% | — | Not comparable |
| Toolathlon-VerifiedSource | — | 49.7% | Not comparable |
CodingGPT-5.6 Terra wins8 benchmarks
| Benchmark | GPT-5.6 Terra | Laguna S 2.1 | Result |
|---|---|---|---|
| SWE-bench ProSource | 63.4% | 59.4% | GPT-5.6 Terra leads |
| Terminal-Bench 2.0Source | 87.4% | 70.2% | GPT-5.6 Terra leads |
| deepSweSource | 69.6% | 40.4% | GPT-5.6 Terra leads |
| FrontierCode 1.1 ExtendedSource | 55.8% | — | Not comparable |
| cursorBench32Source | 64.9% | — | Not comparable |
| AA Coding IndexSource | 76.7% | — | Not comparable |
| AA-SciCodeSource | 53.9% | — | Not comparable |
| SWE MultilingualSource | — | 78.5% | Not comparable |
Reasoning3 benchmarks
Knowledge10 benchmarks
| Benchmark | GPT-5.6 Terra | Laguna S 2.1 | Result |
|---|---|---|---|
| GPQASource | 92.9% | — | Not comparable |
| GPQA-DSource | 92.9% | — | Not comparable |
| HealthBench ProfessionalSource | 57.7% | — | Not comparable |
| HealthBench HardSource | 32.7% | — | Not comparable |
| Artificial Analysis Intelligence IndexSource | 55.0% | — | Not comparable |
| AA-GPQA DiamondSource | 92.5% | — | Not comparable |
| AA-HLESource | 41.8% | — | Not comparable |
| AA-Omniscience IndexSource | -0.2% | — | Not comparable |
| AA-Omniscience AccuracySource | 45.9% | — | Not comparable |
| AA-Omniscience Hallucination RateSource | 85.2% | — | Not comparable |
Math3 benchmarks
Multimodal3 benchmarks
Inst. Following1 benchmarks
| Benchmark | GPT-5.6 Terra | Laguna S 2.1 | Result |
|---|---|---|---|
| AA-IFBenchSource | 71.2% | — | Not comparable |
Frequently Asked Questions (3)
Which is better, GPT-5.6 Terra or Laguna S 2.1?
GPT-5.6 Terra and Laguna S 2.1 are tied on the BenchAlign overall score, so the right pick depends on which category matters most for your use case.
Which is better for coding, GPT-5.6 Terra or Laguna S 2.1?
GPT-5.6 Terra has the edge for coding in this comparison, averaging 63.4 versus 59.4. Inside this category, deepSwe is the benchmark that creates the most daylight between them.
Which is better for agentic tasks, GPT-5.6 Terra or Laguna S 2.1?
GPT-5.6 Terra has the edge for agentic tasks in this comparison, averaging 87.4 versus 70.2. Inside this category, Terminal-Bench 2.0 is the benchmark that creates the most daylight between them.
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