Best AI for coding / head-to-head

GLM 5.2 vs GPT-5.6 Lunafor coding

The verdict

GPT-5.6 Luna wins, 9392

Same 18 coding tasks, marked blind by three rival labs. GPT-5.6 Luna took 5 tasks, GLM 5.2 took 4, 9 tied. Tested 16 Aug 2026.

Where they differed most

The task — Typed debounce

Write a debounce function in TypeScript that preserves the argument types of the wrapped function, returns a function with a .cancel() method, and does not use 'any'. Explain in one sentence why the naive generic signature loses type information.

Here is the TypeScript debounce function:

```typescript
function debounce<A extends unknown[]>(
  func: (...args: A) => unknown,
  wait: number
): ((...args: A) => void) & { cancel: () => void } {
  let timeoutId: ReturnType<typeof setTimeout> | undefined;

  const debounced = ((...args: A): void => {
    if (timeoutId !== undefined) {
      clearTimeout(timeoutId);
    }
    timeoutId = setTimeout(() => func(...args), wait);
  }) as ((...args: A) => void) & { cancel: () => void };

  debounced.cancel = () => {
    if (timeoutId !== undefined)…
```ts
type Debounced<F extends (...args: never[]) => unknown> =
  ((...args: Parameters<F>) => void) & {
    cancel(): void;
  };

function debounce<F extends (...args: never[]) => unknown>(
  fn: F,
  delay: number
): Debounced<F> {
  let timer: ReturnType<typeof setTimeout> | undefined;
  let pendingArgs: Parameters<F> | undefined;

  const debounced = ((...args: Parameters<F>): void => {
    pendingArgs = args;

    if (timer !== undefined) {
      clearTimeout(timer);
    }

    timer = setTimeout(() => {
      const argsToUse = pendingArgs…

Task by task

TaskGLM 5.2GPT-5.6 Luna
Duration parser89
Find the bug1010
SQL without window functions1010
Infinite useEffect109
Typed debounce810
Leftmost binary search1010
Security review99
Safe migration78
Fix the code not the test1010
Race condition910
Retry with backoff109
Recursive type109
Bash one-liner109
Explain and cost99
Regex with limits88
Callback to async1010
Diagnose from a trace88
Idempotency910

Full receipts: GLM 5.2, GPT-5.6 Luna · judges claude-sonnet-5, gemini-3.1-pro-preview, gpt-5.6-terra

Questions people ask

Which is better for coding: GLM 5.2 or GPT-5.6 Luna?

GPT-5.6 Luna — it scored 93/100 against 92/100 on our 18-task coding suite, winning 5 tasks to 4 with 9 tied. Every answer was marked blind by three judges from three rival AI labs.

How was this tested?

Both models answered the identical published coding tasks. Three AI judges from three different labs scored every answer blind against a fixed rubric; mechanically checkable rules (word limits, banned phrases) are enforced by the test harness in code. The raw outputs and judge verdicts are downloadable.

More coding head-to-heads: GPT-5.6 Luna vs GPT-5.6 Sol · GPT-5.6 Luna vs GPT-5.6 Terra · GPT-5.3-Codex vs GPT-5.6 Luna · GPT-5.5 vs GPT-5.6 Luna · GPT-5.6 Luna vs Qwen3.7 Max · Claude Opus 4.8 vs GPT-5.6 Luna

Full ranking: Best AI for coding · model pages: GLM 5.2, GPT-5.6 Luna