GPT-6.1 Sol · Coding

GPT-6.1 Sol for coding: our test runs

GPT-6.1 Sol 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 September 29, 2026, through OpenRouter with the app's own prompt and settings. Updated September 29, 2026.

Short answer

In our test runs on September 29, 2026, GPT-6.1 Sol passed 5 of 5 of our coding prompts (both hard ones): tied 1st of 17 models. Each reply counted as 1 message on Pro, where it has 125 a month, and cost $0.0023 to run on average.

Prompt by prompt

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

GPT-6.1 Sol on each coding prompt
Prompt	Result	Cost	Time
Turn a title into a URL slugEveryday	Passed: All 7 tests passed.	$0.0008	1.7 s
Parse a duration like “1h 30m”Everyday	Passed: All 10 tests passed.	$0.0020	4.8 s
Merge overlapping intervalsEveryday	Passed: All 7 tests passed.	$0.0011	2.0 s
Evaluate an arithmetic expression, no evalHard	Passed: All 15 tests passed.	$0.0037	7.8 s
Parse CSV with quoted fieldsHard	Passed: All 8 tests passed.	$0.0038	8.4 s

Every coding reply from GPT-6.1 Sol

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, "");
}
```
```
485 tokens in, 71 out · 1.7 s · $0.0008 · 1 message on Pro · answered by openai/gpt-6.1-sol via OpenAI · September 29, 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 = /^\s*(?:(\d+)h\s*)?(?:(\d+)m\s*)?(?:(\d+)s\s*)?$/.exec(text);
  if (!match || match.slice(1).every(part => part === undefined)) {
    return null;
  }

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

470 tokens in, 313 out (180 of them reasoning) · 4.8 s · $0.0020 · 1 message on Pro · answered by openai/gpt-6.1-sol via OpenAI · September 29, 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;
}
```

451 tokens in, 127 out · 2.0 s · $0.0011 · 1 message on Pro · answered by openai/gpt-6.1-sol via OpenAI · September 29, 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 pos = 0;

  function skipSpaces() {
    while (pos < expression.length && /\s/.test(expression[pos])) {
      pos++;
    }
  }

  function take(char) {
    skipSpaces();
    if (expression[pos] === char) {
      pos++;
      return true;
    }
    return false;
  }

  function invalid() {
    throw new Error(`Invalid expression at position ${pos}`);
  }

  function primary() {
    skipSpaces();

    if (take("(")) {
      const value = additive();
      if (!take(")")) invalid();
      return value;
    }

    const match = /^(?:\d+(?:\.\d*)?|\.\d+)/.exec(expression.slice(pos));
    if (!match) invalid();

    pos += match[0].length;
    return Number(match[0]);
  }

  function power() {
    const base = primary();
    // Parsing the exponent as unary permits 2^-1 and right-associative powers.
    return take("^") ? base ** unary() : base;
  }

  function unary() {
    return take("-") ? -unary() : power();
  }

  function multiplicative() {
    let value = unary();

    while (true) {
      if (take("*")) value *= unary();
      else if (take("/")) value /= unary();
      else return value;
    }
  }

  function additive() {
    let value = multiplicative();

    while (true) {
      if (take("+")) value += multiplicative();
      else if (take("-")) value -= multiplicative();
      else return value;
    }
  }

  const result = additive();
  skipSpaces();
  if (pos !== expression.length) invalid();

  return result;
}
```

551 tokens in, 632 out (228 of them reasoning) · 7.8 s · $0.0037 · 1 message on Pro · answered by openai/gpt-6.1-sol via OpenAI · September 29, 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;
  let rowStarted = false;

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

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

  if (rowStarted) {
    row.push(field);
    rows.push(row);
  }

  return rows;
}
```

483 tokens in, 665 out (344 of them reasoning) · 8.4 s · $0.0038 · 1 message on Pro · answered by openai/gpt-6.1-sol via OpenAI · September 29, 2026

How it compares on coding

GPT-6.1 Sol beside the job's picks among every model. 15 models share the hard-problems pick, GPT-6.1 Sol among them.

GPT-6.1 Sol beside other models on coding
Model	Passed	On Pro	Cost per reply
GLM 5.3Our pick: hard problems (shared), best value	5 of 5	250 a month on Pro	$0.0015
GLM 5.3 FlashOur pick: hard problems (shared), everyday	5 of 5	60 a day on Pro	$0.0003
GPT-6.1 SolOur pick: hard problems (shared)	5 of 5	125 a month on Pro	$0.0023

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: 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 Sol next to each model on coding

GPT-6.1 Sol 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 Sol answered 1.2× sooner (4.8 s to 5.5 s), cost 18.5× less, and passed 5 of 5 to its 5.
Against Claude Opus 5.5: GPT-6.1 Sol answered 1.5× sooner (4.8 s to 7.2 s), cost 7.4× less, and passed 5 of 5 to its 5.
Against Claude Sonnet 5.5: GPT-6.1 Sol answered 2.4× later (4.8 s to 2.0 s), cost 2.7× less, and passed 5 of 5 to its 5.
Against Claude Sonnet 5: GPT-6.1 Sol answered 1.8× later (4.8 s to 2.7 s), cost 4.4× less, and passed 5 of 5 to its 5.
Against Claude Haiku 4.5: GPT-6.1 Sol answered 2.0× later (4.8 s to 2.3 s), cost 1.2× less, and passed 5 of 5 to its 3. Only GPT-6.1 Sol passed Evaluate an arithmetic expression, no eval; Parse CSV with quoted fields.
Against GPT-6 Astra: GPT-6.1 Sol answered 1.7× sooner (4.8 s to 8.2 s), cost 9.7× less, and passed 5 of 5 to its 5.
Against GPT-6 Sol: GPT-6.1 Sol answered within 10% of its time (4.8 s to 4.8 s), cost 2.3× less, and passed 5 of 5 to its 5.
Against GPT-6 Luna: GPT-6.1 Sol answered within 10% of its time (4.8 s to 4.6 s), cost 8.0× more, and passed 5 of 5 to its 5.
Against Gemini 3.1 Pro (preview): GPT-6.1 Sol answered 2.2× sooner (4.8 s to 10.3 s), cost 8.5× less, and passed 5 of 5 to its 5.
Against Gemini 3.8 Flash: GPT-6.1 Sol answered 1.1× later (4.8 s to 4.2 s), cost 1.2× more, and passed 5 of 5 to its 5.
Against DeepSeek V4.1 Flash: GPT-6.1 Sol answered 1.6× sooner (4.8 s to 7.8 s), cost 2.1× more, and passed 5 of 5 to its 5.
Against DeepSeek V4 Pro: GPT-6.1 Sol answered 4.2× sooner (4.8 s to 20.1 s), cost 5.8× less, and passed 5 of 5 to its 4. Only GPT-6.1 Sol passed Parse CSV with quoted fields.
Against Grok 4.7: GPT-6.1 Sol answered 5.3× sooner (4.8 s to 25.3 s), cost 9.6× less, and passed 5 of 5 to its 5.
Against Kimi K3: GPT-6.1 Sol answered 1.2× later (4.8 s to 4.1 s), cost 2.8× less, and passed 5 of 5 to its 5.
Against GLM 5.3: GPT-6.1 Sol answered 4.5× later (4.8 s to 1.1 s), cost 1.6× more, and passed 5 of 5 to its 5.
Against GLM 5.3 Flash: GPT-6.1 Sol answered 1.8× sooner (4.8 s to 8.4 s), cost 9.1× more, and passed 5 of 5 to its 5.

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 Sol, and coding, elsewhere

Questions

Is GPT-6.1 Sol good for coding?

In our test runs it passed 5 of 5 coding prompts, tied 1st of the 17 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 Sol use?

1 message each on Pro, where it has 125 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, and GLM, in one chat.

See what a message costs before you send it. Free is 5 messages to try; sign in with an email link, no password or card.