Claude vs ChatGPT for coding

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.

Coding: Claude Haiku 5.5 passed 5 of 5 and GPT-6 Luna 5 of 5. Claude Haiku 5.5 answered 1.2× sooner at the median, 3.9 s against 4.6 s. GPT-6 Luna cost 1.6× less, $0.0023 against $0.0014 for the 5 replies. Claude Haiku 5.5's replies ran 71% longer, in tokens of reply, thinking not counted.

1. 1. Turn a title into a URL slug

   Everyday. Claude: 6 of 6 models passed, Claude Haiku 5.5 the cheapest at $0.0001 · GPT: 4 of 4 models passed, GPT-6 Luna the cheapest at $0.0001. The prompt in full.

   Claude Haiku 5.5 and GPT-6 Luna both passed this one. Claude Haiku 5.5 answered sooner (1.5 s to 2.3 s), and GPT-6 Luna's reply cost less ($0.0001 to $0.0001); Claude Haiku 5.5 wrote 112 tokens of reply, GPT-6 Luna 74.

   • Claude Haiku 5.5

     Passed: All 7 tests passed.

     ```javascript
     function slugify(title) {
       return String(title)
         .normalize("NFD")
         .replace(/[\u0300-\u036f]/g, "")
         .toLowerCase()
         .replace(/[^a-z0-9]+/g, "-")
         .replace(/^-+|-+$/g, "");
     }
     ```

     672 tokens in, 112 out · 1.5 s · $0.0001 · 1 message on Pro · answered by anthropic/claude-haiku-5.5 via Anthropic · October 7, 2026

   • GPT-6 Luna

     Passed: All 7 tests passed.

     ```javascript
     function slugify(title) {
       return title
         .toLowerCase()
         .normalize("NFD")
         .replace(/[\u0300-\u036f]/g, "")
         .replace(/[^a-z0-9]+/g, "-")
         .replace(/^-|-$/g, "");
     }
     ```

     483 tokens in, 74 out · 2.3 s · $0.0001 · 1 message on Pro · answered by openai/gpt-6-luna via OpenAI · September 27, 2026

2. 2. Parse a duration like “1h 30m”

   Everyday. Claude: 6 of 6 models passed, Claude Haiku 5.5 the cheapest at $0.0005 · GPT: 4 of 4 models passed, GPT-6 Luna the cheapest at $0.0003. The prompt in full.

   Claude Haiku 5.5 and GPT-6 Luna both passed this one. GPT-6 Luna answered sooner (4.6 s to 5.4 s), and GPT-6 Luna's reply cost less ($0.0003 to $0.0005); Claude Haiku 5.5 wrote 180 tokens of reply, GPT-6 Luna 138.

   • Claude Haiku 5.5

     Passed: All 10 tests passed.

     ```javascript
     function parseDuration(text) {
       if (typeof text !== 'string') return null;
     
       const m = /^\s*(?:(\d+)h)?\s*(?:(\d+)m)?\s*(?:(\d+)s)?\s*$/.exec(text);
       if (!m || m.slice(1).every(v => v === undefined)) return null;
     
       const [, h = 0, mi = 0, s = 0] = m;
       return Number(h) * 3600 + Number(mi) * 60 + Number(s);
     }
     ```

     627 tokens in, 868 out (688 of them reasoning) · 5.4 s · $0.0005 · 1 message on Pro · answered by anthropic/claude-haiku-5.5 via Anthropic · October 7, 2026

   • GPT-6 Luna

     Passed: All 10 tests passed.

     ```javascript
     function parseDuration(text) {
       if (typeof text !== "string") return null;
     
       const match = text.match(/^\s*(?:(\d+)h)?\s*(?:(\d+)m)?\s*(?:(\d+)s)?\s*$/);
       if (!match || !match[1] && !match[2] && !match[3]) return null;
     
       return Number(match[1] || 0) * 3600
         + Number(match[2] || 0) * 60
         + Number(match[3] || 0);
     }
     ```

     468 tokens in, 407 out (269 of them reasoning) · 4.6 s · $0.0003 · 1 message on Pro · answered by openai/gpt-6-luna via OpenAI · September 27, 2026

3. 3. Merge overlapping intervals

   Everyday. Claude: 6 of 6 models passed, Claude Haiku 5.5 the cheapest at $0.0002 · GPT: 4 of 4 models passed, GPT-6 Luna the cheapest at $0.0001. The prompt in full.

   Claude Haiku 5.5 and GPT-6 Luna both passed this one. Claude Haiku 5.5 answered sooner (1.3 s to 1.5 s), and GPT-6 Luna's reply cost less ($0.0001 to $0.0002); Claude Haiku 5.5 wrote 185 tokens of reply, GPT-6 Luna 130.

   • Claude Haiku 5.5

     Passed: All 7 tests passed.

     ```javascript
     function mergeIntervals(intervals) {
       const sorted = intervals
         .map(([start, end]) => [start, end])
         .sort((a, b) => a[0] - b[0] || a[1] - b[1]);
     
       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;
     }
     ```

     622 tokens in, 185 out · 1.3 s · $0.0002 · 1 message on Pro · answered by anthropic/claude-haiku-5.5 via Anthropic · October 7, 2026

   • GPT-6 Luna

     Passed: All 7 tests passed.

     ```javascript
     function mergeIntervals(intervals) {
       const sorted = intervals
         .map(([start, end]) => [start, end])
         .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]) {
           merged.push([start, end]);
         } else {
           last[1] = Math.max(last[1], end);
         }
       }
     
       return merged;
     }
     ```

     449 tokens in, 130 out · 1.5 s · $0.0001 · 1 message on Pro · answered by openai/gpt-6-luna via OpenAI · September 27, 2026

4. 4. Evaluate an arithmetic expression, no eval

   Hard. Claude: 5 of 6 models passed, Claude Haiku 5.5 the cheapest at $0.0006 · GPT: 4 of 4 models passed, GPT-6 Luna the cheapest at $0.0006. The prompt in full.

   Claude Haiku 5.5 and GPT-6 Luna both passed this one. Claude Haiku 5.5 answered sooner (3.9 s to 8.8 s), and GPT-6 Luna's reply cost less ($0.0006 to $0.0006); Claude Haiku 5.5 wrote 1,074 tokens of reply, GPT-6 Luna 552.

   • Claude Haiku 5.5

     Passed: All 15 tests passed.

     ```javascript
     function evaluate(expression) {
       const s = String(expression);
       const tokens = [];
       let i = 0;
       while (i < s.length) {
         const c = s[i];
         if (c === ' ' || c === '\t' || c === '\n' || c === '\r') { i++; continue; }
         if ((c >= '0' && c <= '9') || c === '.') {
           let j = i;
           while (j < s.length && ((s[j] >= '0' && s[j] <= '9') || s[j] === '.')) j++;
           const text = s.slice(i, j);
           if (!/^(\d+\.?\d*|\.\d+)$/.test(text)) throw new Error(`Invalid number "${text}"`);
           tokens.push({ type: 'num', value: Number(text) });
           i = j;
           continue;
         }
         if ('+-*/^()'.includes(c)) {
           tokens.push({ type: c });
           i++;
           continue;
         }
         throw new Error(`Unexpected character "${c}"`);
       }
     
       let pos = 0;
       const peek = () => tokens[pos] ? tokens[pos].type : null;
       const next = () => tokens[pos++];
     
       // expr := term (('+'|'-') term)*
       function parseExpr() {
         let value = parseTerm();
         while (peek() === '+' || peek() === '-') {
           const op = next().type;
           const rhs = parseTerm();
           value = op === '+' ? value + rhs : value - rhs;
         }
         return value;
       }
     
       // term := unary (('*'|'/') unary)*
       function parseTerm() {
         let value = parseUnary();
         while (peek() === '*' || peek() === '/') {
           const op = next().type;
           const rhs = parseUnary();
           value = op === '*' ? value * rhs : value / rhs;
         }
         return value;
       }
     
       // unary := '-' unary | power
       function parseUnary() {
         if (peek() === '-') {
           next();
           return -parseUnary();
         }
         return parsePower();
       }
     
       // power := primary ('^' unary)?   (right-associative; exponent may be signed)
       function parsePower() {
         const base = parsePrimary();
         if (peek() === '^') {
           next();
           const exp = parseUnary();
           return Math.pow(base, exp);
         }
         return base;
       }
     
       // primary := number | '(' expr ')'
       function parsePrimary() {
         const t = tokens[pos];
         if (!t) throw new Error('Unexpected end of expression');
         if (t.type === 'num') {
           pos++;
           return t.value;
         }
         if (t.type === '(') {
           pos++;
           const value = parseExpr();
           if (peek() !== ')') throw new Error('Expected ")"');
           pos++;
           return value;
         }
         throw new Error(`Unexpected token "${t.type}"`);
       }
     
       if (tokens.length === 0) throw new Error('Empty expression');
       const result = parseExpr();
       if (pos !== tokens.length) throw new Error(`Unexpected token "${tokens[pos].type}"`);
       return result;
     }
     ```

     763 tokens in, 1,074 out · 3.9 s · $0.0006 · 1 message on Pro · answered by anthropic/claude-haiku-5.5 via Anthropic · October 7, 2026

   • GPT-6 Luna

     Passed: All 15 tests passed.

     ```javascript
     function evaluate(expression) {
       if (typeof expression !== "string") {
         throw new Error("Expression must be a string");
       }
     
       let index = 0;
     
       function skipSpaces() {
         while (index < expression.length && /\s/.test(expression[index])) {
           index++;
         }
       }
     
       function parsePrimary() {
         skipSpaces();
     
         if (expression[index] === "(") {
           index++;
           const value = parseExpression();
           skipSpaces();
           if (expression[index] !== ")") throw new Error("Missing closing parenthesis");
           index++;
           return value;
         }
     
         const start = index;
         let digitsBefore = 0;
         while (/\d/.test(expression[index] || "")) {
           index++;
           digitsBefore++;
         }
     
         let digitsAfter = 0;
         if (expression[index] === ".") {
           index++;
           while (/\d/.test(expression[index] || "")) {
             index++;
             digitsAfter++;
           }
         }
     
         if (digitsBefore === 0 && digitsAfter === 0) {
           throw new Error("Expected a number or parenthesized expression");
         }
     
         return Number(expression.slice(start, index));
       }
     
       // Unary minus has lower precedence than exponentiation, but is allowed
       // on an exponent's right-hand side.
       function parseUnary() {
         skipSpaces();
         if (expression[index] === "-") {
           index++;
           return -parseUnary();
         }
         return parsePower();
       }
     
       function parsePower() {
         let value = parsePrimary();
         skipSpaces();
     
         if (expression[index] === "^") {
           index++;
           value **= parseUnary();
         }
     
         return value;
       }
     
       function parseProduct() {
         let value = parseUnary();
     
         while (true) {
           skipSpaces();
           const operator = expression[index];
           if (operator !== "*" && operator !== "/") break;
     
           index++;
           const right = parseUnary();
           value = operator === "*" ? value * right : value / right;
         }
     
         return value;
       }
     
       function parseExpression() {
         let value = parseProduct();
     
         while (true) {
           skipSpaces();
           const operator = expression[index];
           if (operator !== "+" && operator !== "-") break;
     
           index++;
           const right = parseProduct();
           value = operator === "+" ? value + right : value - right;
         }
     
         return value;
       }
     
       const result = parseExpression();
       skipSpaces();
       if (index !== expression.length) throw new Error("Unexpected input");
     
       return result;
     }
     ```

     549 tokens in, 1,007 out (455 of them reasoning) · 8.8 s · $0.0006 · 1 message on Pro · answered by openai/gpt-6-luna via OpenAI · September 27, 2026

5. 5. Parse CSV with quoted fields

   Hard. Claude: 5 of 6 models passed, Claude Haiku 5.5 the cheapest at $0.0008 · GPT: 4 of 4 models passed, GPT-6 Luna the cheapest at $0.0004. The prompt in full.

   Claude Haiku 5.5 and GPT-6 Luna both passed this one. GPT-6 Luna answered sooner (7.2 s to 8.1 s), and GPT-6 Luna's reply cost less ($0.0004 to $0.0008); Claude Haiku 5.5 wrote 516 tokens of reply, GPT-6 Luna 315.

   • Claude Haiku 5.5

     Passed: All 8 tests passed.

     ```javascript
     function parseCsv(text) {
       const rows = [];
       if (text === '') return rows;
     
       let row = [];
       let field = '';
       let inQuotes = false;
       let fieldStart = true; // true only at the very beginning of a field
       let i = 0;
       const n = text.length;
     
       while (i < n) {
         const c = text[i];
     
         if (inQuotes) {
           if (c === '"') {
             if (text[i + 1] === '"') {
               field += '"';
               i += 2;
             } else {
               inQuotes = false;
               i++;
             }
           } else {
             field += c;
             i++;
           }
           continue;
         }
     
         if (c === '"' && fieldStart) {
           inQuotes = true;
           fieldStart = false;
           i++;
           continue;
         }
     
         if (c === ',') {
           row.push(field);
           field = '';
           fieldStart = true;
           i++;
           continue;
         }
     
         if (c === '\n' || c === '\r') {
           row.push(field);
           rows.push(row);
           row = [];
           field = '';
           fieldStart = true;
           if (c === '\r' && text[i + 1] === '\n') i += 2;
           else i++;
           continue;
         }
     
         field += c;
         fieldStart = false;
         i++;
       }
     
       // Flush the last row unless the text ended with a line break
       if (row.length > 0 || field !== '' || !fieldStart) {
         row.push(field);
         rows.push(row);
       }
     
       return rows;
     }
     ```

     670 tokens in, 1,464 out (948 of them reasoning) · 8.1 s · $0.0008 · 1 message on Pro · answered by anthropic/claude-haiku-5.5 via Anthropic · October 7, 2026

   • GPT-6 Luna

     Passed: All 8 tests passed.

     ```javascript
     function parseCsv(text) {
       if (text === "") return [];
     
       const rows = [];
       let row = [];
       let field = "";
       let inQuotes = false;
       let endedWithRowBreak = false;
     
       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;
           }
           endedWithRowBreak = false;
           continue;
         }
     
         if (char === '"' && field === "") {
           inQuotes = true;
           endedWithRowBreak = false;
         } else if (char === ",") {
           row.push(field);
           field = "";
           endedWithRowBreak = false;
         } else if (char === "\n" || (char === "\r" && text[i + 1] === "\n")) {
           row.push(field);
           rows.push(row);
           row = [];
           field = "";
           if (char === "\r") i++;
           endedWithRowBreak = true;
         } else {
           field += char;
           endedWithRowBreak = false;
         }
       }
     
       if (!endedWithRowBreak) {
         row.push(field);
         rows.push(row);
       }
     
       return rows;
     }
     ```

     481 tokens in, 762 out (447 of them reasoning) · 7.2 s · $0.0004 · 1 message on Pro · answered by openai/gpt-6-luna via OpenAI · September 27, 2026

• Claude Fable 5.1 vs GPT-6 Astra: 5 of 5 each; Claude Fable 5.1 answered 1.5× sooner at the median and GPT-6 Astra cost 1.9× less. Claude Fable 5.1 vs GPT-6 Astra, on every job.

• Claude Fable 5.1 vs GPT-6.1 Sol: 5 of 5 each; GPT-6.1 Sol answered 1.2× sooner at the median and cost 18.5× less.

• Claude Fable 5.1 vs GPT-6 Sol: 5 of 5 each; GPT-6 Sol answered 1.2× sooner at the median and cost 8.1× less.

• Claude Fable 5.1 vs GPT-6 Luna: 5 of 5 each; GPT-6 Luna answered 1.2× sooner at the median and cost 148.3× less.

• Claude Opus 5.5 vs GPT-6 Astra: 5 of 5 each; Claude Opus 5.5 answered 1.1× sooner at the median and cost 1.3× less. Claude Opus 5.5 vs GPT-6 Astra, on every job.

• Claude Opus 5.5 vs GPT-6.1 Sol: 5 of 5 each; GPT-6.1 Sol answered 1.5× sooner at the median and cost 7.4× less.

• Claude Opus 5.5 vs GPT-6 Sol: 5 of 5 each; GPT-6 Sol answered 1.5× sooner at the median and cost 3.3× less. Claude Opus 5.5 vs GPT-6 Sol, on every job.

• Claude Opus 5.5 vs GPT-6 Luna: 5 of 5 each; GPT-6 Luna answered 1.6× sooner at the median and cost 59.5× less.

• Claude Sonnet 5.5 vs GPT-6 Astra: 5 of 5 each; Claude Sonnet 5.5 answered 4.2× sooner at the median and cost 3.6× less.

• Claude Sonnet 5.5 vs GPT-6.1 Sol: 5 of 5 each; Claude Sonnet 5.5 answered 2.4× sooner at the median and GPT-6.1 Sol cost 2.7× less. GPT-6.1 Sol vs Claude Sonnet 5.5, on every job.

• Claude Sonnet 5.5 vs GPT-6 Sol: 5 of 5 each; Claude Sonnet 5.5 answered 2.5× sooner at the median and GPT-6 Sol cost 1.2× less. Claude Sonnet 5.5 vs GPT-6 Sol, on every job.

• Claude Sonnet 5.5 vs GPT-6 Luna: 5 of 5 each; Claude Sonnet 5.5 answered 2.3× sooner at the median and GPT-6 Luna cost 21.8× less.

• Claude Sonnet 5 vs GPT-6 Astra: 5 of 5 each; Claude Sonnet 5 answered 3.1× sooner at the median and cost 2.2× less.

• Claude Sonnet 5 vs GPT-6.1 Sol: 5 of 5 each; Claude Sonnet 5 answered 1.8× sooner at the median and GPT-6.1 Sol cost 4.4× less.

• Claude Sonnet 5 vs GPT-6 Sol: 5 of 5 each; Claude Sonnet 5 answered 1.8× sooner at the median and GPT-6 Sol cost 1.9× less. Claude Sonnet 5 vs GPT-6 Sol, on every job.

• Claude Sonnet 5 vs GPT-6 Luna: 5 of 5 each; Claude Sonnet 5 answered 1.7× sooner at the median and GPT-6 Luna cost 35.4× less.

• Claude Haiku 4.5 vs GPT-6 Astra: Claude Haiku 4.5 3 of 5, GPT-6 Astra 5; Claude Haiku 4.5 answered 3.5× sooner at the median and cost 8.1× less.

• Claude Haiku 4.5 vs GPT-6.1 Sol: Claude Haiku 4.5 3 of 5, GPT-6.1 Sol 5; Claude Haiku 4.5 answered 2.0× sooner at the median and GPT-6.1 Sol cost 1.2× less.

• Claude Haiku 4.5 vs GPT-6 Sol: Claude Haiku 4.5 3 of 5, GPT-6 Sol 5; Claude Haiku 4.5 answered 2.0× sooner at the median and cost 1.9× less. Claude Haiku 4.5 vs GPT-6 Sol, on every job.

• Claude Haiku 4.5 vs GPT-6 Luna: Claude Haiku 4.5 3 of 5, GPT-6 Luna 5; Claude Haiku 4.5 answered 1.9× sooner at the median and GPT-6 Luna cost 9.6× less. Claude Haiku 4.5 vs GPT-6 Luna, on every job.

• Claude Haiku 5.5 vs GPT-6 Astra: 5 of 5 each; Claude Haiku 5.5 answered 2.1× sooner at the median and cost 49.3× less.

• Claude Haiku 5.5 vs GPT-6.1 Sol: 5 of 5 each; Claude Haiku 5.5 answered 1.2× sooner at the median and cost 5.1× less.

• Claude Haiku 5.5 vs GPT-6 Sol: 5 of 5 each; Claude Haiku 5.5 answered 1.2× sooner at the median and cost 11.6× less.

• Claude Haiku 5.5 vs GPT-6 Luna: 5 of 5 each; Claude Haiku 5.5 answered 1.2× sooner at the median and GPT-6 Luna cost 1.6× less. Claude Haiku 5.5 vs GPT-6 Luna, on every job.

Every Claude and GPT reply above was checked the same way as every other model's, by the rules published with the prompts: how the coding prompts are scored, and each one in full.

• The lineups

  Claude: 6 models, Claude Fable 5.1, Claude Opus 5.5, Claude Sonnet 5.5, Claude Sonnet 5, Claude Haiku 4.5, and Claude Haiku 5.5. GPT: 4 models, GPT-6 Astra, GPT-6.1 Sol, GPT-6 Sol, and GPT-6 Luna.

• Price per message

  The least expensive Claude model is Claude Haiku 5.5 (60 messages a day on Pro); the least expensive GPT model is GPT-6 Luna (60 messages a day on Pro).

• Context window

  Claude goes up to 1M tokens (Claude Fable 5.1); GPT up to 1.05M tokens (GPT-6 Astra).

• Images and PDFs

  Every model here reads images. Every model here takes a PDF as a whole file.

• On the Free plan

  Free's one-time trial of 5 messages covers Claude Sonnet 5.5, Claude Sonnet 5, Claude Haiku 4.5, Claude Haiku 5.5, GPT-6.1 Sol, GPT-6 Sol, and GPT-6 Luna, and Claude Opus 5.5 for 1 message. Paid plans have every model, with messages every month.

In llmwise, a message to Claude or GPT goes to the model's maker, or through OpenRouter when llmwise can't reach the maker directly. The Privacy Policy has the details.