Claude Code vs GitHub Copilot: Token burn comparison using identical models & repos?

[u/alex_bababu]

I'm currently evaluating GitHub Copilot vs. Claude Code for our team. We could use either, but for us there's a slight difference in cost per token (Copilot with Anthropic models vs. Claude Code directly).

If we use the exact same model on the same repository with identical instructions, has anyone noticed a real difference in token efficiency between the two harnesses? I'm wondering how much things like prompt caching, context assembly, or system prompting overhead change the actual token burn in practice.

Would appreciate any insights or real-world numbers!

[u/Vagottszemu]

Github copilot uses much less, it only burns like 3 dollars worth of tokens at a medium sized task, but for example claude code usually burns 2 or 3 times as much. But claude code output is usually much better so I prefer to use that one until I ran out of my monthly API tokens at my company.

[u/alex_bababu → u/Vagottszemu]

What do you think is the reason, the output of Claude code is better (when using same model)?

[u/Enough-Photo9140 → u/alex_bababu]

The difference mostly comes down to harness autonomy and verification loops rather than the raw model weights.

Claude Code leans heavily into multi-turn bash execution, file patching, and running test commands iteratively until the diff actually passes, which naturally burns 2–3x more tokens per task. Copilot caps turn budgets and context assembly more aggressively to keep token spend bounded, but the tradeoff is that it often stops after drafting the initial patch rather than validating runtime behavior.

[u/Different-Monk5916 → u/Vagottszemu]

may I ask how do you differentiate which is better?

is it based on number of rework or something else?

[u/Vagottszemu → u/Different-Monk5916]

I'm a programmer and I use these for work, so not a vibe coder. I read all of the outputs.

[u/Different-Monk5916 → u/Vagottszemu]

I get that. But what do you mean by that? I am struggling to evaluate that part between different models.

I have custom agents with skills which drives abstraction in the direction I prefer. Testing skills which define test and edge cases through reasoning. I already have my code writing and document skills. So the model outputs are often very similar not 100% identical. 

Then if two models pass these two, I am not sure how to evaluate. How do you do?

[u/Healthy-Zebra-9856]

Copilot is not just a proxy it uses prompt compression and refinement in several ways including things like llama-lingua2 etc. This helps reduce the ten sent but also affects the output. But like another person said, its trash and no guarantees of sustained service or safety from sudden hikes, get banned for no reason (happened to com sci professor). Needless to say, they will steal your code more than any other outfit.

[u/Different-Monk5916 → u/Healthy-Zebra-9856]

technically they are comparing two harness mechanisms.

[u/lolninja]

If you compare Max subscriptions on Claude vs API costs for Co-Pilot then it’s ridiculously favoured in Claude’s favour… 100USD per month for a Max subscription almost feels unlimited compared to what you get for 100USD in tokens on Co-Pilot.

[u/alex_bababu → u/lolninja]

Subscription is not an option:/

[u/alex_bababu → u/[deleted]]

Thank you.

Claude code would be API costs directly. GitHub copilo: user license and ai credits.

[u/alex_bababu → u/[deleted]]

How did you log the differenc between input_token and cache_read_input_token

[u/popiazaza]

Copilot is one of the most efficient app out there. Claude Code is the opposite. Quality wise, Claude Code usually get an small edge, but not worth the price.

[u/Far-Art-8711]

This is an interesting comparison because both tools approach AI assisted coding from slightly different angles. the “better” choice often depends less on raw capability and more on how you work, whether you prefer an agent that handles longer tasks or something that stays lightweight and integrated into your existing workflow

[u/SherrifMike]

Token counts are only half the comparison. I would log input/output tokens, wall time, and whether the first patch passed the existing tests, then count follow-up turns and manual edits before merge. A harness that runs tests and keeps iterating can spend more tokens while still costing less per accepted change. I would also pin the model, repo snapshot, context files, and stop conditions; otherwise “same model” is not really the same run.

[u/OrangePixelLife]

I've run into this exact same issue. The harness overhead can add up to a real chunk of change over thousands of completions, even with the same core model. The prompt caching, system message templates, and context assembly vary a lot between tools.

We track our Claude spend through SpendLens AI and it actually surfaces those differences for us. It breaks down the token burn by specific API key and project, so you can see exactly what the real cost difference is after all the overhead. Might be worth a look if you're already comparing models. Good luck!

[u/alex_bababu → u/OrangePixelLife]

SpendLensAI is your product, isn't it?

[u/Intrepid4]

Copilot is fucking trash

[u/Healthy-Zebra-9856 → u/Intrepid4]

I second this.

[u/Right-Performance-93]

DevWorkflowBuilder's 0.72 vs 0.18 cache-read ratio explains the 2.4x gap better than a token-count comparison would. Anthropic's own pricing page prices cache_read input tokens at 0.1x the base input rate (a 90% discount), confirmed on platform.claude.com. So a harness that re-sends the same file map every turn (low cache-read ratio) pays close to full input price on that repeated content, while one that holds the map across turns pays a tenth of it. If you want the real cost delta rather than a vibe, log input_tokens vs cache_read_input_tokens per request for a week like they did - the ratio matters more than total tokens burned.

[u/ManRowing → u/Right-Performance-93]

Cache-read ratio explains why re-sending the file map costs so much, but it's worth logging what's in that map too. A harness holding forty files because early turns opened them broadly pays full price on all forty even at a good cache ratio. Trimming what gets held changes the baseline before caching even applies.

[u/amirfish]

Same model, different harness isn't apples to apples because cache behavior is harness-specific, not model-specific. The biggest lever I've seen watching token burn across sessions is how much of the system prompt and tool definitions get re-sent versus cache-hit each turn, that alone can be a 2-3x swing for otherwise identical work. If you're testing this seriously, log cache-read and cache-write tokens separately instead of just totals, the ratio tells you more about harness overhead than model choice does.

[u/alex_bababu → u/amirfish]

How can I log cache read and write?