Grok vs Claude for Coding: Compared Side by Side

On a real coding task, Grok and Claude wrote nearly identical solutions, same approach, same edge-case handling, both correct. When the code itself is a wash, the comparison comes down to one number, and here that number was cost. Grok produced its answer for roughly a fifth of what Claude charged. Same working code, very different bill.

The run

The whole setup behind the numbers:

Prompt: one Python coding task (below), asking for a function, a docstring, edge-case handling, and a brief complexity note.
Models: Grok grok-4.7 and Claude claude-opus-5-5.
Settings: each model’s default, temperature 0.7, no system prompt, no extra context.
Keys: our own, calling each provider directly. One real run.

Prompt

Write a Python function merge_intervals(intervals) that takes a list of [start, end] integer pairs, merges all overlapping intervals, and returns the merged list sorted by start. Include a docstring and handle the empty-input and single-interval cases. Then briefly explain the time complexity.

The result, side by side

Grok (grok-4.7)

Correct: yes
Cost: $0.0045 (about 5x cheaper)
Speed: 5.9 seconds
Length: 318 tokens
Style: compact, clear docstring, concise complexity note

Claude (claude-opus-5-5)

Correct: yes
Cost: $0.0242
Speed: 9.7 seconds
Length: 1,189 tokens
Style: detailed docstring, worked examples, a test block

The two solutions were close enough to be near twins, down to copying the first interval so the input is not mutated:

Grok (grok-4.7)

def merge_intervals(intervals):
    """Merge overlapping [start, end] intervals, sorted by start. Empty input returns []."""
    if not intervals:
        return []
    if len(intervals) == 1:
        return [list(intervals[0])]
    sorted_intervals = sorted(intervals, key=lambda iv: iv[0])
    merged = [list(sorted_intervals[0])]
    for start, end in sorted_intervals[1:]:
        if start <= merged[-1][1]:
            merged[-1][1] = max(merged[-1][1], end)
        else:
            merged.append([start, end])
    return merged

Concise, with an O(n log n) note.

Claude (claude-opus-5-5)

def merge_intervals(intervals):
    """Merge overlapping intervals, sorted by start. Input is not modified."""
    if not intervals:
        return []
    if len(intervals) == 1:
        return [list(intervals[0])]
    sorted_intervals = sorted(intervals, key=lambda iv: iv[0])
    merged = [list(sorted_intervals[0])]
    for start, end in sorted_intervals[1:]:
        last = merged[-1]
        if start <= last[1]:
            last[1] = max(last[1], end)
        else:
            merged.append([start, end])
    return merged

The same logic, plus worked examples, a test block, and a separate space-complexity note.

Both are correct and structurally the same. The difference you can act on is cost and how much surrounding explanation you want.

Insight: When two models land on effectively the same code, paying more does not buy you a better answer, it buys more documentation. For a routine function where the solution is well known, the cheaper model is often the rational pick. Where cost is the only thing separating two correct answers, it should drive the decision. Run it on your own task to see whether the code really is a wash for you.

These results come from a specific run on 2026-11-02 on one defined task, using real models through a real pipeline. They show how each model performed on that task, not a general ranking of model quality, which depends entirely on your task and data. Run your own to see your numbers.

Run it on your own coding task

The free tool below opens with Grok and Claude ready to go, and the prompt is editable:

Click Launch to open the notebook.
Swap in your own coding task and add your own API keys.
Read both answers side by side with their cost and speed, in about a minute.

Nothing is sent to our servers, and your keys stay on your machine.

Want to go further? At llmprover.pysolvr.com you can score the code against your own checks, compare up to 20 models at once, and see which part of your setup caused a weak answer.

Run as of 2026-11-02. Models and their prices change often, so run a fresh comparison to see today’s result on your own coding task.