GPT-6.1 Terra · Coding

GPT-6.1 Terra for coding: our test runs

GPT-6.1 Terra ran our 5 coding prompts in llmwise, through the same pipeline your messages take. Here's every reply as it came, whether it passed, what it cost and what it counts as on Pro, next to the other models.

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Based on 5 of our test runs on October 27, 2026, through OpenRouter with the app's own prompt and settings. Updated November 2, 2026.

Short answer

In our test runs on October 27, 2026, GPT-6.1 Terra passed 5 of 5 of our coding prompts (both hard ones): tied 1st of 21 models. Each reply counted as 1 message on Pro, where it has 250 a month, and cost $0.0014 to run on average.

Prompt by prompt

Each of the 5 coding prompts, and how GPT-6.1 Terra's reply did.

GPT-6.1 Terra on each coding prompt
Prompt	Result	Cost	Time
Turn a title into a URL slugEveryday	Passed: All 7 tests passed.	$0.0006	2.4 s
Parse a duration like “1h 30m”Everyday	Passed: All 10 tests passed.	$0.0018	5.5 s
Merge overlapping intervalsEveryday	Passed: All 7 tests passed.	$0.0006	2.5 s
Evaluate an arithmetic expression, no evalHard	Passed: All 15 tests passed.	$0.0020	4.6 s
Parse CSV with quoted fieldsHard	Passed: All 8 tests passed.	$0.0017	4.7 s

Every coding reply from GPT-6.1 Terra

Turn a title into a URL slug
An everyday prompt: “Turn a title into a URL slug”, in full.
Passed: All 7 tests passed.
```
```javascript
function slugify(title) {
  return title
    .toLowerCase()
    .normalize("NFD")
    .replace(/\p{M}/gu, "")
    .replace(/[^a-z0-9]+/g, "-")
    .replace(/^-+|-+$/g, "");
}
```
```
657 tokens in, 121 out (48 of them reasoning) · 2.4 s · $0.0006 · 1 message on Pro · answered by openai/gpt-6.1-terra via OpenAI · October 27, 2026

Parse a duration like “1h 30m”

An everyday prompt: “Parse a duration like “1h 30m””, in full.

Passed: All 10 tests passed.

```javascript
function parseDuration(text) {
  if (typeof text !== "string") return null;

  const match = text.match(/^ *(?:(\d+)h)? *(?:(\d+)m)? *(?:(\d+)s)? *$/);
  if (!match || match[0] !== text || !match.slice(1).some(Boolean)) {
    return null;
  }

  return Number(match[1] || 0) * 3600
    + Number(match[2] || 0) * 60
    + Number(match[3] || 0);
}
```

642 tokens in, 594 out (461 of them reasoning) · 5.5 s · $0.0018 · 1 message on Pro · answered by openai/gpt-6.1-terra via OpenAI · October 27, 2026

Merge overlapping intervals

An everyday prompt: “Merge overlapping intervals”, in full.

Passed: All 7 tests passed.

```javascript
function mergeIntervals(intervals) {
  const sorted = intervals.map(([start, end]) => [start, end]);
  sorted.sort((a, b) => a[0] - b[0]);

  const merged = [];

  for (const [start, end] of sorted) {
    const last = merged[merged.length - 1];

    if (last && start <= last[1]) {
      last[1] = Math.max(last[1], end);
    } else {
      merged.push([start, end]);
    }
  }

  return merged;
}
```

623 tokens in, 127 out · 2.5 s · $0.0006 · 1 message on Pro · answered by openai/gpt-6.1-terra via OpenAI · October 27, 2026

Evaluate an arithmetic expression, no eval

A hard prompt: “Evaluate an arithmetic expression, no eval”, in full.

Passed: All 15 tests passed.

```javascript
function evaluate(expression) {
  if (typeof expression !== "string") {
    throw new Error("Expression must be a string");
  }

  let position = 0;

  function peek() {
    while (position < expression.length && /\s/.test(expression[position])) {
      position++;
    }
    return expression[position];
  }

  function parsePrimary() {
    if (peek() === "(") {
      position++;
      const value = parseSum();
      if (peek() !== ")") throw new Error("Expected closing parenthesis");
      position++;
      return value;
    }

    const match = /^(?:\d+(?:\.\d*)?|\.\d+)/.exec(expression.slice(position));
    if (!match) throw new Error("Expected a number or parenthesis");
    position += match[0].length;
    return Number(match[0]);
  }

  function parsePower() {
    const base = parsePrimary();
    if (peek() === "^") {
      position++;
      return base ** parseUnary();
    }
    return base;
  }

  function parseUnary() {
    if (peek() === "-") {
      position++;
      return -parseUnary();
    }
    return parsePower();
  }

  function parseProduct() {
    let value = parseUnary();
    while (peek() === "*" || peek() === "/") {
      const operator = expression[position++];
      const right = parseUnary();
      value = operator === "*" ? value * right : value / right;
    }
    return value;
  }

  function parseSum() {
    let value = parseProduct();
    while (peek() === "+" || peek() === "-") {
      const operator = expression[position++];
      const right = parseProduct();
      value = operator === "+" ? value + right : value - right;
    }
    return value;
  }

  const result = parseSum();
  if (peek() !== undefined) throw new Error("Unexpected character");
  return result;
}
```

723 tokens in, 659 out (242 of them reasoning) · 4.6 s · $0.0020 · 1 message on Pro · answered by openai/gpt-6.1-terra via OpenAI · October 27, 2026

Parse CSV with quoted fields

A hard prompt: “Parse CSV with quoted fields”, in full.

Passed: All 8 tests passed.

```javascript
function parseCsv(text) {
  if (text === "") return [];

  const rows = [];
  let row = [];
  let field = "";
  let inQuotes = false;
  let atFieldStart = true;

  for (let i = 0; i < text.length; i++) {
    const char = text[i];

    if (inQuotes) {
      if (char === '"') {
        if (text[i + 1] === '"') {
          field += '"';
          i++;
        } else {
          inQuotes = false;
        }
      } else {
        field += char;
      }
    } else if (char === '"' && atFieldStart) {
      inQuotes = true;
      atFieldStart = false;
    } else if (char === ",") {
      row.push(field);
      field = "";
      atFieldStart = true;
    } else if (char === "\n" || (char === "\r" && text[i + 1] === "\n")) {
      if (char === "\r") i++;
      row.push(field);
      rows.push(row);

      if (i === text.length - 1) return rows;

      row = [];
      field = "";
      atFieldStart = true;
    } else {
      field += char;
      atFieldStart = false;
    }
  }

  row.push(field);
  rows.push(row);
  return rows;
}
```

655 tokens in, 565 out (262 of them reasoning) · 4.7 s · $0.0017 · 1 message on Pro · answered by openai/gpt-6.1-terra via OpenAI · October 27, 2026

How it compares on coding

GPT-6.1 Terra beside the job's picks among every model. 19 models share the hard-problems pick, GPT-6.1 Terra among them.

GPT-6.1 Terra beside other models on coding
Model	Passed	On Pro	Cost per reply
GPT-6.1 TerraOur pick: hard problems (shared), best value	5 of 5	250 a month on Pro	$0.0014
GLM 5.3 FlashOur pick: hard problems (shared), everyday	5 of 5	60 a day on Pro	$0.0003

On Pro: Pro's count on each model. Cost: what OpenRouter charged us per reply, on average.

Every limit is published. Paid plans also have a monthly fair-use limit on AI cost: Plus $3.75, Pro $7.50, Max $20, Ultra $42, Studio $85. Using every message on your plan at typical sizes stays under it; very large messages and heavy research use it faster. Every limit, explained.

GPT-6.1 Terra next to each model on coding

GPT-6.1 Terra against each model on the same 5 coding prompts. One run each, through OpenRouter: a wait depends on the provider and the load that day, so a lead under 10% counts as close.

Against Claude Fable 5.1: GPT-6.1 Terra answered 1.2× sooner (4.6 s to 5.5 s), cost 31.2× less, and passed 5 of 5 to its 5.
Against Claude Opus 5.5: GPT-6.1 Terra answered 1.6× sooner (4.6 s to 7.2 s), cost 12.5× less, and passed 5 of 5 to its 5.
Against Claude Sonnet 5.5: GPT-6.1 Terra answered 2.3× later (4.6 s to 2.0 s), cost 4.6× less, and passed 5 of 5 to its 5.
Against Claude Sonnet 5: GPT-6.1 Terra answered 1.7× later (4.6 s to 2.7 s), cost 7.5× less, and passed 5 of 5 to its 5.
Against Claude Haiku 5.5: GPT-6.1 Terra answered 1.2× later (4.6 s to 3.9 s), cost 3.0× more, and passed 5 of 5 to its 5.
Against Claude Haiku 4.5: GPT-6.1 Terra answered 1.9× later (4.6 s to 2.3 s), cost 2.0× less, and passed 5 of 5 to its 3. Only GPT-6.1 Terra passed Evaluate an arithmetic expression, no eval; Parse CSV with quoted fields.
Against GPT-6 Astra: GPT-6.1 Terra answered 1.8× sooner (4.6 s to 8.2 s), cost 16.4× less, and passed 5 of 5 to its 5.
Against GPT-6.1 Sol: GPT-6.1 Terra answered within 10% of its time (4.6 s to 4.8 s), cost 1.7× less, and passed 5 of 5 to its 5.
Against GPT-6 Sol: GPT-6.1 Terra answered within 10% of its time (4.6 s to 4.8 s), cost 3.9× less, and passed 5 of 5 to its 5.
Against GPT-6 Luna: GPT-6.1 Terra answered within 10% of its time (4.6 s to 4.6 s), cost 4.8× more, and passed 5 of 5 to its 5.
Against Gemini 4 Argon: GPT-6.1 Terra answered 1.3× later (4.6 s to 3.5 s), cost 1.8× less, and passed 5 of 5 to its 5.
Against Gemini 3.1 Pro (preview): GPT-6.1 Terra answered 2.2× sooner (4.6 s to 10.3 s), cost 14.3× less, and passed 5 of 5 to its 5.
Against Gemini 3.8 Flash: GPT-6.1 Terra answered within 10% of its time (4.6 s to 4.2 s), cost 1.4× less, and passed 5 of 5 to its 5.
Against DeepSeek V4.1 Flash: GPT-6.1 Terra answered 1.8× later (4.6 s to 2.5 s), cost 1.3× less, and passed 5 of 5 to its 5.
Against DeepSeek V4 Pro: GPT-6.1 Terra answered 26.2× sooner (4.6 s to 119.6 s), cost 17.6× less, and passed 5 of 5 to its 5.
Against Grok 4.7: GPT-6.1 Terra answered 6.9× sooner (4.6 s to 31.6 s), cost 18.0× less, and passed 5 of 5 to its 5.
Against Kimi K3: GPT-6.1 Terra answered 1.1× later (4.6 s to 4.1 s), cost 4.6× less, and passed 5 of 5 to its 5.
Against GLM 5.3: GPT-6.1 Terra answered 4.3× later (4.6 s to 1.1 s), cost within 10% of it, and passed 5 of 5 to its 5.
Against GLM 5.3 Flash: GPT-6.1 Terra answered 1.8× sooner (4.6 s to 8.4 s), cost 5.4× more, and passed 5 of 5 to its 5.
Against Mistral Large 4: GPT-6.1 Terra answered 8.0× sooner (4.6 s to 36.8 s), cost 5.3× less, and passed 5 of 5 to its 4. Only GPT-6.1 Terra passed Evaluate an arithmetic expression, no eval.

How these runs were done

Tests. Automatic. The function runs against the prompt's tests in a separate Node.js process with a time limit and no file, network or child-process access; it passes when every test passes.

How the runs were done, and every coding prompt.

GPT-6.1 Terra, and coding, elsewhere

Questions

Is GPT-6.1 Terra good for coding?

In our test runs it passed 5 of 5 coding prompts, tied 1st of the 21 models in llmwise. Every reply is on this page, so you can judge them yourself.

How many of my messages does a coding reply from GPT-6.1 Terra use?

1 message each on Pro, where it has 250 a month on Pro. The price of a message is fixed and shown before you send it, however long the reply.

How were these runs done?

The same way for every model: each prompt sent through llmwise's own pipeline, each reply checked the same way. The methods page has every prompt and how each is scored.

Claude, GPT, Gemini, DeepSeek, Grok, Kimi, GLM, and Mistral, in one chat.

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