Model comparison
GPT-5.6 Terra vs Grok 4.5
Head-to-head evidence from 22 shared benchmark results across 5 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.
Public leaderboard positions: GPT-5.6 Terra #11 (Estimated); Grok 4.5 #7 (Supported). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.
Evidence parity. GPT-5.6 Terra and Grok 4.5 share 22 comparable benchmark results. 2 of 8 categories are comparable. 22 results are unique to GPT-5.6 Terra; 6 to Grok 4.5.
Updated July 23, 2026- Shared results
- 22
- GPT-5.6 Terra only
- 22
- Grok 4.5 only
- 6
- Comparable categories
- 2 / 8
Pick Grok 4.5 if you want the stronger benchmark profile. GPT-5.6 Terra only becomes the better choice if agentic is the priority or you need the larger 1M context window.
Confidence note. This is a partial-evidence comparison with 22 shared benchmark results across 5 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
Grok 4.5 is clearly ahead on the BenchAlign aggregate, 76.72 to 72.57. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.
Grok 4.5's sharpest advantage is in coding, where it averages 64.7 against 63.4. The single biggest benchmark swing on the page is Terminal-Bench 2.0, 87.4% to 83.3%. GPT-5.6 Terra does hit back in agentic, so the answer changes if that is the part of the workload you care about most.
GPT-5.6 Terra is also the more expensive model on tokens at $2.50 input / $15.00 output per 1M tokens, versus $2.00 input / $6.00 output per 1M tokens for Grok 4.5. That is roughly 2.5x on output cost alone. GPT-5.6 Terra gives you the larger context window at 1M, compared with 500K for Grok 4.5.
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 | Grok 4.5 |
|---|---|---|---|
| Agentic | GPT-5.6 Terra87.4 | Margin← 4.1 | Grok 4.583.3 |
| Coding | GPT-5.6 Terra63.4 | Margin→ 1.3 | Grok 4.564.7 |
| Knowledge | GPT-5.6 Terra92.9 | MarginNo overlap | Grok 4.5Not measured |
| Math | GPT-5.6 Terra80.8 | MarginNo overlap | Grok 4.5Not measured |
| Multimodal | GPT-5.6 Terra80.7 | MarginNo overlap | Grok 4.5Not 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 83.3%Winner: GPT-5.6 TerraΔ 4.1Terminal-Bench 2.0: GPT-5.6 Terra scored 87.4%; Grok 4.5 scored 83.3%. GPT-5.6 Terra wins this benchmark. - Source ↗
SWE-bench Pro
CodingA 63.4%B 64.7%Winner: Grok 4.5Δ 1.3SWE-bench Pro: GPT-5.6 Terra scored 63.4%; Grok 4.5 scored 64.7%. Grok 4.5 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 | Grok 4.5 | Comparison |
|---|---|---|---|
| Input / output priceUSD per 1M tokens | GPT-5.6 Terra$2.5 input / $15 output | Grok 4.5$2 input / $6 output | Grok 4.5 has the lower combined listed price. |
| Generation speedtokens per second | GPT-5.6 TerraNot available | Grok 4.5Not available | A complete speed comparison is not available. |
| First-answer latencyseconds to first token | GPT-5.6 TerraNot available | Grok 4.5Not available | A complete latency comparison is not available. |
| Context windowmaximum listed tokens | GPT-5.6 Terra1M | Grok 4.5500K | GPT-5.6 Terra lists the larger context window. |
Benchmark Deep Dive
AgenticGPT-5.6 Terra wins20 benchmarks
| Benchmark | GPT-5.6 Terra | Grok 4.5 | Result |
|---|---|---|---|
| Terminal-Bench 2.0Source | 87.4% | 83.3% | 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% | 45.7% | GPT-5.6 Terra leads |
| τ²-bench resultsSource | 86.3% | — | Not comparable |
| GDPval-AASource | 54.1% | 51.7% | GPT-5.6 Terra leads |
| GDPval-AASource | 1581 | 1535 | GPT-5.6 Terra leads |
| AA Harvey LABSource | 85.2% | 92.4% | Grok 4.5 leads |
| AA ITBenchSource | 51.0% | — | Not comparable |
| AA Tau3 BankingSource | 31.8% | 32.6% | Grok 4.5 leads |
| AA AutomationBenchSource | 45.6% | 51.4% | Grok 4.5 leads |
| terminalBenchHardSource | 57.6% | — | Not comparable |
| aaTerminalBench21Source | 88% | 81.6% | GPT-5.6 Terra leads |
| APEX-Agents-AASource | 38.9% | — | Not comparable |
| deepSweSource | — | 53% | Not comparable |
| AA BriefcaseSource | — | 1323 | Not comparable |
| AA EnterpriseOps-GymSource | — | 40.8% | Not comparable |
CodingGrok 4.5 wins9 benchmarks
| Benchmark | GPT-5.6 Terra | Grok 4.5 | Result |
|---|---|---|---|
| SWE-bench ProSource | 63.4% | 64.7% | Grok 4.5 leads |
| Terminal-Bench 2.0Source | 87.4% | 83.3% | GPT-5.6 Terra leads |
| deepSweSource | 69.6% | — | Not comparable |
| FrontierCode 1.1 ExtendedSource | 55.8% | — | Not comparable |
| cursorBench32Source | 64.9% | 66.7% | Grok 4.5 leads |
| AA Coding IndexSource | 76.7% | 72.5% | GPT-5.6 Terra leads |
| AA-SciCodeSource | 53.9% | 54.1% | Grok 4.5 leads |
| SWE MultilingualSource | — | 78% | Not comparable |
| VulcanBench v3Source | — | 91.3% | Not comparable |
Reasoning3 benchmarks
Knowledge10 benchmarks
| Benchmark | GPT-5.6 Terra | Grok 4.5 | 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% | 53.8% | GPT-5.6 Terra leads |
| AA-GPQA DiamondSource | 92.5% | 93.1% | Grok 4.5 leads |
| AA-HLESource | 41.8% | 40.3% | GPT-5.6 Terra leads |
| AA-Omniscience IndexSource | -0.2% | 26.4% | Grok 4.5 leads |
| AA-Omniscience AccuracySource | 45.9% | 52.1% | Grok 4.5 leads |
| AA-Omniscience Hallucination RateSource | 85.2% | 53.5% | Grok 4.5 leads |
Math3 benchmarks
Multimodal4 benchmarks
Inst. Following1 benchmarks
| Benchmark | GPT-5.6 Terra | Grok 4.5 | Result |
|---|---|---|---|
| AA-IFBenchSource | 71.2% | — | Not comparable |
Frequently Asked Questions (3)
Which is better, GPT-5.6 Terra or Grok 4.5?
Grok 4.5 is ahead on BenchLM's BenchAlign leaderboard, 76.72 to 72.57. The biggest single separator in this matchup is Terminal-Bench 2.0, where the scores are 87.4% and 83.3%.
Which is better for coding, GPT-5.6 Terra or Grok 4.5?
Grok 4.5 has the edge for coding in this comparison, averaging 64.7 versus 63.4. Inside this category, AA Coding Index is the benchmark that creates the most daylight between them.
Which is better for agentic tasks, GPT-5.6 Terra or Grok 4.5?
GPT-5.6 Terra has the edge for agentic tasks in this comparison, averaging 87.4 versus 83.3. Inside this category, GDPval-AA is the benchmark that creates the most daylight between them.
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