GPT-5.3-Codex vs GPT-6.1 Terra
Full profiles: GPT-5.3-Codex (OpenAI) and GPT-6.1 Terra (OpenAI): every benchmark, price and rank.
Updated · Data from 5 sources
As of 27 Oct 2026, GPT-5.3-Codex (xhigh) and GPT-6.1 Terra (max) are neck and neck on quality (63.6 vs 65.9 on the BenchLeader Index, inside the ±8.5 margin of error), and GPT-6.1 Terra (max) costs 2.4× less, which makes it the better buy for most workloads. GPT-6.1 Terra leads in every category we measure both in.
GPT-5.3-Codex benchmarks xhigh OpenAI GPT-6.1 Terra benchmarks max OpenAIOpen in the comparison toolWhich to pick for…
The pick's numbers come first. Category scores on the BenchLeader scale (50 is the average model, 15 points one standard deviation). High confidence means a lead of half a standard deviation or more; under one point is called either.
| Use case | Pick | Why | Confidence |
|---|---|---|---|
| Reasoning | GPT-6.1 Terra | 86 vs 68 category score; CritPt 28.0% vs 16.9% | High |
| Knowledge | GPT-6.1 Terra | 75 vs 66 category score; AA-Omniscience 29.8 vs 10.9 | High |
| Long documents | Either | 67 vs 66 category score; AA-LCR 83.3% vs 82.7% | Either |
| Images and other media | GPT-6.1 Terra | 68 vs 61 category score; MMMU-Pro 84.7% vs 78.5% | Medium |
| Lowest cost | GPT-6.1 Terra | $2.00 vs $4.81 per 1M blended; agentic coding session $0.080 vs $0.161 | – |
| Fastest first answer | GPT-5.3-Codex | 55.9 s (GPT-5.3-Codex (xhigh)) vs 131.8 s (GPT-6.1 Terra (max)) to the first answer token | – |
| High volume on a budget | Neither flagship | A smaller model is usually the better fit: Cheapest good LLMs, Fastest LLMs | – |
Key differences
- GPT-5.3-Codex (xhigh) and GPT-6.1 Terra (max) are neck and neck on quality (63.6 vs 65.9, within the ±8.5 margin).
- GPT-5.3-Codex (xhigh) is stronger in agents & tools, coding, instruction following, long context.
- GPT-6.1 Terra (max) is stronger in composite, knowledge, multimodal, reasoning.
- GPT-6.1 Terra (max) is 2.4× cheaper ($2.00 vs $4.81 per 1M blended).
At a glance
| Spec | GPT-5.3-Codex | GPT-6.1 Terra |
|---|---|---|
| Developer | OpenAI | OpenAI |
| Released | 5 Feb 2026 | 26 Oct 2026 |
| Context window (tokens) | 400,000 | 1,050,000 |
| Compared at | GPT-5.3-Codex (xhigh) | GPT-6.1 Terra (max) |
| Open weights | No | No |
| Price in / out / cached input per 1M | $1.75 / $14.00 / $0.175 | $1.00 / $5.00 / $0.050 |
Category by category
Category scores on the BenchLeader scale: 50 is the average evaluated model, 15 points is one standard deviation. A gap under one point is called level.
| Category | GPT-5.3-Codex (xhigh) | GPT-6.1 Terra (max) | Leader |
|---|---|---|---|
| Reasoning | 68.1 | 86.2 | GPT-6.1 Terra |
| Coding | 60.8 | – | not comparable |
| Agents & tools | 80.1 | – | not comparable |
| Knowledge | 66.0 | 74.5 | GPT-6.1 Terra |
| Instruction following | 73.5 | – | not comparable |
| Multimodal | 61.2 | 67.5 | GPT-6.1 Terra |
| Long context | 66.6 | 66.3 | level |
| Composite | 65.4 | 82.8 | GPT-6.1 Terra |
Where sources disagree
Across the 7 benchmarks both have, GPT-5.3-Codex leads 2, GPT-6.1 Terra leads 5. Every overall index that rates both puts GPT-6.1 Terra ahead.
| Overall index | GPT-5.3-Codex (xhigh) | GPT-6.1 Terra (max) | Leader |
|---|---|---|---|
| BenchLeader Index | 63.6 | 65.9 | neck and neck |
| AA Intelligence Index v4.3.2 | 32.5 | 48.1 | GPT-6.1 Terra |
Each publisher runs its own tasks, harnesses and effort settings, so their overall verdicts can differ; BenchLeader reconciles them on one scale. † measured at another effort setting of the same model (the publisher did not test the one compared here).
Price, speed and latency
List prices blended at three input tokens per output token. Per-task prices use the token counts on the methodology page; suite cost is what Artificial Analysis paid to run its whole Intelligence Index.
| Measure | GPT-5.3-Codex (xhigh) | GPT-6.1 Terra (max) |
|---|---|---|
| Blended price per 1M tokens | $4.81 | $2.00 |
| Input / output per 1M | $1.75 / $14.00 | $1.00 / $5.00 |
| Cached input per 1M | $0.175 | $0.050 |
| Price per task: chat reply | $0.0049 | $0.0019 |
| Price per task: summarize a 30-page report | $0.029 | $0.015 |
| Price per task: code edit | $0.032 | $0.013 |
| Price per task: agentic coding session | $0.161 | $0.080 |
| Price per task: structured extraction | $0.0063 | $0.0030 |
| Cost to run a full benchmark suite | – | $0.403 |
| Output speed | 103 tok/s | 91 tok/s |
| Time to first answer | 55.9 s | 131.8 s |
| Time to a complete answer | 60.8 s | 137.3 s |
Each model is compared at its best-ranked reasoning-effort setting. GPT-5.3-Codex (xhigh) scores 63.6 and takes 56 s to its first answer token. GPT-6.1 Terra (max) scores 65.9 and takes 132 s to its first answer token; GPT-6.1 Terra (xhigh) scores 65.0 in 18 s, GPT-6.1 Terra (high) scores 64.7 in 7 s. Higher effort means more thinking before the answer: better scores, longer waits and more tokens billed. How reasoning effort changes scores and cost.
Every benchmark
42 benchmarks, grouped by category; each name links to the board and its leaders. † measured at another effort setting of the same model, shown for reference and not counted as a win.
| Metric | Publisher | GPT-5.3-Codex (xhigh) | GPT-6.1 Terra (max) |
|---|---|---|---|
| BenchLeader Index | BenchLeader | 63.6 | 65.9 |
| Agents & tools score | BenchLeader | 80.1 | – |
| Coding score | BenchLeader | 60.8 | – |
| Composite score | BenchLeader | 65.4 | 82.8 |
| Instruction following score | BenchLeader | 73.5 | – |
| Knowledge score | BenchLeader | 66.0 | 74.5 |
| Long context score | BenchLeader | 66.6 | 66.3 |
| Multimodal score | BenchLeader | 61.2 | 67.5 |
| Reasoning score | BenchLeader | 68.1 | 86.2 |
| Blended price $/M | BenchLeader | $4.81 | $2.00 |
| Output speed | BenchLeader | 103 tok/s | 91 tok/s |
| Time to first answer | BenchLeader | 55.9 s | 131.8 s |
| Context window | BenchLeader | 400,000 tokens | 1,050,000 tokens |
| Reasoning | |||
| LiveBench 2.0 Reasoning | LiveBench | – | 88.7%† |
| GPQA Diamond (AA) | Artificial Analysis | 91.5% | – |
| Humanity's Last Exam (AA) | Artificial Analysis | 42.5% | 46.3% |
| CritPt | Artificial Analysis | 16.9% | 28.0% |
| Coding | |||
| SWE-bench Verified (Epoch) | Epoch AI Benchmarking Hub | 74.8%† | – |
| WeirdML | WeirdML | 77.9% | – |
| Arena WebDev | Arena (LMArena) | 1407† | – |
| LiveBench 2.0 Coding | LiveBench | – | 90.8%† |
| SciCode (AA) | Artificial Analysis | – | 55.1% |
| LiveCodeBench | Vals AI | 87.3% | – |
| IOI | Vals AI | 53.8% | – |
| SWE-bench (Vals) | Vals AI | 78.0% | – |
| Vibe Code Bench v1.1 | Vals AI | 61.8% | – |
| ALE-Bench | Epoch AI Benchmarking Hub | 1655.2 | – |
| Terminal-Bench 4.0 (AA) | Artificial Analysis | – | 55.6% |
| FrontierCode 1.1 (AA) | Artificial Analysis | – | 36.0% |
| Agents & tools | |||
| Terminal-Bench | Terminal-Bench | 78.4%† | – |
| LiveBench Long Agentic | LiveBench | – | 48.6%† |
| LiveBench Browser | LiveBench | – | 93.1%† |
| Terminal-Bench Hard | Artificial Analysis | 53.0% | – |
| τ²-Bench Telecom (AA) | Artificial Analysis | 86.0% | – |
| HiL-Bench | Scale AI SEAL | 4.3%† | – |
| Terminal-Bench 2.0 (Vals) | Vals AI | 64.0%† | – |
| METR Time Horizons | METR | 74.5%† | – |
| Vending-Bench 2 | Andon Labs | 5940.1† | – |
Show all 42 benchmarks
| Metric | Publisher | GPT-5.3-Codex (xhigh) | GPT-6.1 Terra (max) |
|---|---|---|---|
| Agents & tools | |||
| AutomationBench | Artificial Analysis | – | 60.2% |
| GDP.pdf (AA) | Artificial Analysis | – | 28.6% |
| AA-Briefcase v1.1 | Artificial Analysis | – | 1402 |
| Terminal-Bench-Science 0.1 (AA) | Artificial Analysis | – | 57.6% |
| Knowledge | |||
| LiveBench 2.0 Data Analysis | LiveBench | – | 82.3%† |
| LiveBench Research | LiveBench | – | 73.9%† |
| AA-Omniscience | Artificial Analysis | 10.9 | 29.8 |
| AA-Omniscience: accuracy | Artificial Analysis | 52.9% | 49.1% |
| AA-Omniscience: non-hallucination | Artificial Analysis | 10.8% | 62.0% |
| Instruction following | |||
| IFBench | Artificial Analysis | 75.4% | – |
| Multimodal | |||
| LiveBench Design | LiveBench | – | 82.3%† |
| MMMU-Pro | Artificial Analysis | 78.5% | 84.7% |
| Long context | |||
| AA-LCR | Artificial Analysis | 83.3% | 82.7% |
| Composite | |||
| Epoch Capabilities Index | Epoch AI Benchmarking Hub | 157.1† | – |
| LiveBench 2.0 | LiveBench | – | 77.2%† |
| AA Intelligence Index v4.3.2 | Artificial Analysis | 32.5 | 48.1 |
| Safety & honesty | |||
| FORTRESS | Scale AI SEAL | – | 18.2%† |
Data as of 2026-10-27. Best configuration of each model; every score links to its source on the model pages.
What changed
- GPT-5.3-Codex (xhigh): BenchLeader Index 64.4 → 63.9.
- GPT-5.3-Codex (xhigh): BenchLeader Index 64.9 → 64.4.
Related comparisons
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- GPT-6.1 Terra vs Claude Fable 5.1
- GPT-6.1 Terra vs GPT-6 Astra
- GPT-6.1 Terra vs Muse Wonder Full
- GPT-5.3-Codex vs GPT-6.1 Sol
Rankings: Best LLM overall · Best LLM for agents · Best cheap LLMs
GPT-5.3-Codex vs GPT-6.1 Terra: questions
- Is GPT-5.3-Codex better than GPT-6.1 Terra?
- GPT-5.3-Codex (xhigh) and GPT-6.1 Terra (max) are neck and neck on quality (63.6 vs 65.9, within the ±8.5 margin). The BenchLeader Index combines every independent quality benchmark; the two are within the margin of error as of 2026-10-27, so check the category scores for your use.
- Which is cheaper, GPT-5.3-Codex or GPT-6.1 Terra, and will that change?
- GPT-6.1 Terra is cheaper today: $2.00 against $4.81 per million tokens, blended at three input tokens per output token. No price change has been announced for either.
- Which is better for long documents?
- They are level on long-context benchmarks (67 vs 66). GPT-6.1 Terra accepts more context: 1,050,000 against 400,000 tokens for GPT-5.3-Codex.
- Which has lower latency?
- GPT-5.3-Codex (xhigh) answers first: 55.9 s against 131.8 s to the first answer token, as Artificial Analysis measures it. Reasoning effort drives most of this: a higher setting thinks longer before it answers.
- Which is faster, GPT-5.3-Codex or GPT-6.1 Terra?
- GPT-5.3-Codex streams faster: 103 against 91 output tokens per second.
- Do independent benchmarks agree on GPT-5.3-Codex vs GPT-6.1 Terra?
- Across the 7 benchmarks both have, GPT-5.3-Codex leads 2, GPT-6.1 Terra leads 5. Every overall index that rates both puts GPT-6.1 Terra ahead.
- When was GPT-6.1 Terra released?
- GPT-6.1 Terra was released on 26 Oct 2026.