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Free AI code converter

Paste code in one language. Get it back in another, written the way a native developer would, with notes on every behavior that changes.

How it works

  1. Paste a function, class, script or SQL query. Short, self-contained pieces convert most reliably.
  2. Pick the language to convert to (and the source, if detection might guess wrong), add any runtime constraints, and click Convert my code.
  3. Read the Notes on behavior differences, then run the converted code against the same test inputs as the original.

Examples

Sample results for the inputs shown, so you can see the format and quality before you try it.

Example 1: input

Code to convert: def summarize(orders): totals = {} for o in orders: if o["status"] != "cancelled": totals[o["region"]] = totals.get(o["region"], 0) + o["qty"] * o["price"] avg = sum(totals.values()) // len(totals) if totals else 0 return sorted(totals.items(), key=lambda kv: kv[1], reverse=True), avg

Convert to: JavaScript

Convert from: Python

Example 1: output
function summarize(orders) { const totals = new Map(); for (const o of orders) { if (o.status !== "cancelled") { totals.set(o.region, (totals.get(o.region) ?? 0) + o.qty * o.price); } } const values = [...totals.values()]; const avg = values.length ? Math.floor(values.reduce((a, b) => a + b, 0) / values.length) : 0; const ranked = [...totals.entries()].sort((a, b) => b[1] - a[1]); return [ranked, avg]; } Notes: - Python's // rounds down, so the average uses Math.floor, which also rounds negative numbers down the same way. - The Python tuple becomes a two-item array: const [ranked, avg] = summarize(orders). - A missing key raises KeyError in Python; in JavaScript it gives undefined and the total becomes NaN. Validate orders first if that can happen.
Example 2: input

Code to convert: SELECT customer_id, GROUP_CONCAT(DISTINCT product_name ORDER BY product_name SEPARATOR ', ') AS products, IFNULL(SUM(amount), 0) AS total, DATE_FORMAT(MAX(created_at), '%Y-%m') AS last_month FROM orders WHERE created_at >= DATE_SUB(NOW(), INTERVAL 90 DAY) GROUP BY customer_id ORDER BY total DESC LIMIT 20;

Convert to: PostgreSQL

Convert from: MySQL

Example 2: output
SELECT customer_id, STRING_AGG(DISTINCT product_name, ', ' ORDER BY product_name) AS products, COALESCE(SUM(amount), 0) AS total, TO_CHAR(MAX(created_at), 'YYYY-MM') AS last_month FROM orders WHERE created_at >= NOW() - INTERVAL '90 days' GROUP BY customer_id ORDER BY total DESC LIMIT 20; Notes: - GROUP_CONCAT becomes STRING_AGG. MySQL cuts GROUP_CONCAT results at 1,024 characters by default; PostgreSQL doesn't, so long product lists may now come back longer. - IFNULL becomes COALESCE and DATE_FORMAT becomes TO_CHAR with PostgreSQL format codes. - If created_at is timestamp without time zone, NOW() compares in the server's time zone. Use timestamptz if your data spans time zones.
Example 3: input

Code to convert: public static Map<String, Integer> wordCounts(String text) { Map<String, Integer> counts = new HashMap<>(); for (String w : text.toLowerCase().split("\\W+")) { if (w.isEmpty()) continue; counts.merge(w, 1, Integer::sum); } return counts; }

Convert to: Go

Convert from: Java

Example 3: output
package wordcount import ( "regexp" "strings" ) var nonWord = regexp.MustCompile(`\W+`) // WordCounts returns how many times each word appears in text, ignoring case. func WordCounts(text string) map[string]int { counts := make(map[string]int) for _, w := range nonWord.Split(strings.ToLower(text), -1) { if w == "" { continue } counts[w]++ } return counts } Notes: - Both Java's \W and Go's \W are ASCII-only, so words with accents are split the same way in both versions. - Go map iteration order is random, like HashMap. Sort the keys if you print the results. - The regex is compiled once at package level instead of on every call, which is the usual Go pattern.

Tips for better results

  • Convert one function or query at a time and compare outputs on the same inputs. It's the quickest way to catch a subtle difference.
  • Watch division, rounding and missing values. Python's //, JavaScript's single number type and SQL's NULL rules cause most porting bugs.
  • Mention the runtime or version in the notes box (Node 20, Java 17, PostgreSQL 16). It changes which built-in functions are safe to use.
  • Paste the helper functions the code calls. Otherwise the converter leaves a TODO rather than guessing what they do.

FAQ

Is this code converter free?

Yes. Enter your email once to use it (you'll also get Something Big, our free weekly AI newsletter, and you can unsubscribe anytime). There's no account and no credit card.

Which languages can it convert between?

Python, JavaScript, TypeScript, Java, C#, Go, Rust, PHP, Ruby, Kotlin and Swift, plus SQL between PostgreSQL, MySQL and SQL Server.

Is the converted code a word-for-word translation?

No. It keeps the behavior the same but writes the code the way a developer in the target language would, using its own collections, naming and error handling. The notes list every behavior that could differ.

Can it convert a whole project?

It works best on one file, class or function at a time, up to about 6,000 characters. For a full migration, convert piece by piece and test each one.

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