Claude Opus 5 vs Claude Sonnet 5: what the multiplier costs you
Same vendor, same API, two price tiers. This is the decision most Claude API users actually face: pay the frontier rate on everything, or route work by difficulty. The gap in the table below is what that decision is worth And because both sit behind the same endpoint and the same key, it is the cheapest tiering decision on the site to implement: a model-ID change per request, not a new integration.
Claude Opus 5 vs Claude Sonnet 5: the numbers side by side
| Claude Opus 5 | Claude Sonnet 5 | |
|---|---|---|
| Gateway rate — input | $2.5 | $1 |
| Gateway rate — output | $12.5 | $5 |
| Official list — input | $5 | $2 |
| Official list — output | $25 | $10 |
| Blended at 1/3 output | $5.83 | $2.33 |
| Output : input price ratio | 5.0× | 5.0× |
USD per 1M tokens. Gateway rates checked 2026-11-01; official list prices as published by each vendor. Gateway rates move with upstream promotions (re-check before committing a budget).
What each costs per month
| Monthly tokens | Claude Opus 5 | Claude Sonnet 5 | Cheaper |
|---|---|---|---|
| 10M | $58.33 | $23.33 | Claude Sonnet 5 — 60% less |
| 100M | $583 | $233 | Claude Sonnet 5 — 60% less |
| 1000M | $5,833 | $2,333 | Claude Sonnet 5 — 60% less |
Assumes 1/3 of tokens are output and 2/3 input, roughly a chat or coding-agent mix. At a 100M tokens/month workload the gap is $350 a month, or $4,200 a year. Change the split in the calculator (output-heavy workloads widen the gap).
How much tokens each budget buys
| Budget | Claude Opus 5 | Claude Sonnet 5 | Extra tokens |
|---|---|---|---|
| $100 | 17M | 43M | Claude Sonnet 5 — 26M more |
| $1,000 | 171M | 429M | Claude Sonnet 5 — 257M more |
Tokens purchasable at the blended rate above. Output tokens cost more than input, so reading these figures as "all input" would overstate them.
Which one to pick
The routing pattern beats the model choice here. Three workable arrangements:
- All Sonnet. Simplest, one model to reason about, and the right call if your volume is low enough that the difference does not fund the engineering time to route.
- Sonnet with Opus escalation. Run everything on the cheaper model, detect failures or low confidence, re-run only those on the frontier model. You keep most of the saving and cap the quality risk.
- Opus for planning, Sonnet for execution. Use the dearer model once to produce a plan or a spec, then let the cheaper model carry out the mechanical steps. Common in coding agents, where the expensive part is deciding and the cheap part is typing.
The monthly table above is the budget side of that decision. Whether the quality difference is worth the multiplier is a question for your own eval set, the price index should not answer it for you.
Where the answer flips: cost as the output share moves
Both prices above are blended at one third output. That assumption is doing more work than it looks like, because it is the only thing standing between you and the opposite answer. The table below holds volume constant and moves only the output share.
| Output share | Claude Opus 5 | Claude Sonnet 5 | Cheaper | Gap |
|---|---|---|---|---|
| 0% | $2.5 | $1 | Claude Sonnet 5 | $1.5 |
| 10% | $3.5 | $1.4 | Claude Sonnet 5 | $2.1 |
| 25% | $5 | $2 | Claude Sonnet 5 | $3 |
| 33% | $5.8 | $2.32 | Claude Sonnet 5 | $3.48 |
| 50% | $7.5 | $3 | Claude Sonnet 5 | $4.5 |
| 75% | $10 | $4 | Claude Sonnet 5 | $6 |
| 100% | $12.5 | $5 | Claude Sonnet 5 | $7.5 |
Across the whole range one model stays ahead. Claude Sonnet 5 is cheaper at every output share from 0% to 100%, so this choice does not depend on your token shape.
Read the table as the reason not to trust a single number. Most published comparisons quote one blended figure, usually at an assumed ratio, and that figure is only valid at that ratio. The gap column is the one to watch: where it narrows towards zero, the decision should be made on something other than price.
What this comparison does not tell you
A price comparison answers one question and quietly implies several others it has not addressed. Before acting on the numbers above, these are the differences that a rate table cannot show:
- Cost per task, not cost per token. A model that needs half as many turns to finish the same job can be cheaper at a higher rate. The only way to know is to run one representative task on each and compare tokens consumed, not rates charged.
- Context window. A shorter window does not produce an error It produces truncation, which looks like a quality problem and gets misdiagnosed as one. Where your workload depends on long context, this outranks price entirely.
- Latency and throughput. Two models at similar rates can differ enough in response time to change whether a feature is usable. Measure it on your own payloads.
- Availability and rate limits. What you can actually sustain under concurrency is a property of the account and the route, not of the price.
- Capability differences. These pages compare price only. Where a capability difference is decisive, the vendor's own documentation is the source, we do not guess at it, and a cheaper model that cannot do the job is not cheaper.
The honest ordering: if the gap column above is small at your output share, stop optimising price and optimise for whichever of the five items above your workload actually depends on.
Switching between them
Both models are called through the same endpoint, so this is a model-ID change, not a migration. Setup references: OpenAI & Anthropic SDK · Claude Code · Cursor · reducing API cost.
Related comparisons: Three ways to pay for Claude · Claude vs GPT · What Claude Code costs per month
FAQ
Is Claude Opus 5 or Claude Sonnet 5 cheaper?
At current gateway rates Claude Sonnet 5 is cheaper for a mixed workload — $5.83 versus $2.33 per 1M tokens blended at one third output. The answer depends on your input/output split: output tokens are priced several times higher than input on both models (5x and 5x respectively), so an output-heavy workload widens the gap.
How much does Claude Opus 5 cost per month?
At $5.83 per 1M blended tokens: about $58.33 for 10M tokens a month, $583 for 100M, and $5,833 for 1B. That is pure token spend There is no subscription on either model.
How much does Claude Sonnet 5 cost per month?
At $2.33 per 1M blended tokens: about $23.33 for 10M tokens a month, $233 for 100M, and $2,333 for 1B.
Can I switch between them without rewriting my code?
Both are reached through the same gateway endpoint, so switching is a model-ID change in the request rather than a new integration. See the SDK guide for the one-line change, or the Claude Code setup if you are switching inside a coding agent.
Should I run everything on the cheaper model?
Only if your eval set says quality holds. The pattern we would suggest testing first is verification rather than blind substitution: run the cheaper model, detect failures, and escalate only those. That usually captures most of the saving while bounding the risk, and it is measurable before you commit.
Which is cheaper for a coding agent, Claude Opus 5 or Claude Sonnet 5?
Agent workloads are input-heavy. Roughly 500M input to 100M output a month, because every turn resends the whole context. At that shape Claude Opus 5 bills about $2,500.00 and Claude Sonnet 5 about $1,000.00, so Claude Sonnet 5 comes out ahead. The same model wins at both shapes, so this particular choice does not hinge on how output-heavy your workload turns out to be.
What is the price difference between Claude Opus 5 and Claude Sonnet 5 per 1M tokens?
On input it is $2.5 against $1 per 1M; on output, $12.5 against $5. Blended at one third output the gap is $3.5 per 1M in favour of Claude Sonnet 5. Output carries a multiple of the input rate on both models, so the gap widens or narrows with your own token split rather than staying fixed — price it in the calculator with your real ratio before committing.