Claude Opus 4.6 vs Mistral Large 3 2512
AnthropicMistral AIboth via one key, provider price + 3%
Claude Opus 4.6 (Anthropic, released Feb 2026) and Mistral Large 3 2512 (Mistral, released Dec 2025, Apache 2.0, 41B active / 675B total params MoE) sit at opposite ends of the price-performance curve. Opus 4.6 costs 10x more per input token and has a 1M-token context window versus Mistral's 262,144 tokens — a 3.81x ratio. The gap in Design Arena benchmark rank is just as wide. This comparison covers where that gap matters and where it doesn't.
Spec vs spec
| Spec | Claude Opus 4.6 | Mistral Large 3 2512 |
|---|---|---|
| Context window | 1M | 262K |
| Max output | 128K | — |
| Input modalities | text, image, file | text, image, file |
| Output modalities | text | text |
| Released | Feb 4, 2026 | Dec 1, 2025 |
| Reasoning | optional | — |
Pricing
Per 1M tokens. Provider price plus the flat 3% fee — the sum is what you pay.
anthropic/claude-opus-4.6
Input · 1M tokens
$5.00 + 3%$5.15
Output · 1M tokens
$25.00 + 3%$25.75
Cache read · 1M tokens
$0.500 + 3%$0.515
Cache write · 1M tokens
$6.25 + 3%$6.44
FEE — FLAT, EVERY MODEL3%
mistralai/mistral-large-2512
Input · 1M tokens
$0.500 + 3%$0.515
Output · 1M tokens
$1.50 + 3%$1.54
Cache read · 1M tokens
$0.050 + 3%$0.052
FEE — FLAT, EVERY MODEL3%
One workload, priced on both
10M input + 2M output tokens at each model's price, flat 3% fee included.
anthropic/claude-opus-4.6
$103.00
$100.00 provider + 3%
mistralai/mistral-large-2512Cheaper
$8.24
$8.00 provider + 3%
Benchmarks
Design Arena categories where both models have results. Higher Elo and lower rank win.
| Claude Opus 4.6 | Mistral Large 3 2512 | |||
|---|---|---|---|---|
| Category | Elo | Rank | Elo | Rank |
| 3D | 1351 | #4 | 1176 | #51 |
| ASCII art | 1307 | #6 | 1115 | #43 |
| Code | 1342 | #3 | 1191 | #56 |
| Data viz | 1322 | #5 | 1180 | #55 |
| Game dev | 1344 | #4 | 1146 | #65 |
| SVG | 1288 | #4 | 1050 | #62 |
| UI components | 1350 | #3 | 1157 | #59 |
| Websites | 1338 | #3 | 1205 | #53 |
Head-to-head preference voting. How we filter and rank
Pricing math on a real workload
Provider list price: Opus 4.6 runs $5.00/M input and $25.00/M output; Mistral Large runs $0.50/M input and $1.50/M output. On OpenKey, both get the flat 3% fee: Opus 4.6 is $5.15/M input and $25.75/M output ($5.00 x 1.03, $25.00 x 1.03); Mistral Large is $0.515/M input and $1.545/M output.
For a 10M-input / 2M-output workload, that's $100.00 total for Opus 4.6 versus $8.00 for Mistral Large — a 12.5x difference in real spend. If your workload is mostly text generation at scale (support replies, summarization, data extraction), that gap compounds fast. If it's a small number of high-stakes coding or agent runs, the absolute dollars are usually small regardless of which model you pick.
Coding and agent benchmarks
Design Arena tells a clear story. Opus 4.6 ranks 3rd in codecategories (elo 1342, 63.9% win rate) and 3rd in uicomponent (elo 1350, 64.5% win rate). Its agent-arena scores are similarly strong: rank 4 in fullstack (elo 1288), rank 3 in mobileapps (elo 1261), rank 4 in webapps (elo 1266).
Mistral Large's best category is website at rank 53 (elo 1205, 49.4% win rate); codecategories lands at rank 56 (elo 1191, 47.6% win rate). Mistral has no agents-arena entries in this dataset — Opus 4.6 is the only one of the two tested on agentic tasks at all. Mistral's artificial_analysis scores back this up: coding index 20.1 and agentic index 5.5, both well below what you'd want for autonomous coding agents.
Context and long-document work
Opus 4.6 handles up to 1,000,000 tokens of context; Mistral Large 3 2512 caps at 262,144 tokens, a 3.81x smaller window. Opus 4.6 also supports a 128,000-token max completion length, giving it room for long, structured outputs (large refactors, full reports) in a single call. Mistral Large's max completion tokens isn't specified in its config, so treat its practical output ceiling as an unknown you should test rather than assume. For document sets that approach or exceed a quarter-million tokens — long contracts, full codebases, multi-file diffs — Opus 4.6 is the safer default.
Parameters and reasoning control
Opus 4.6 exposes a `reasoning` parameter with four effort levels (max, high, medium, low; default medium) and `verbosity` control, plus `top_k` — useful for tuning how hard the model thinks before answering. Mistral Large 3 2512 has no reasoning parameter at all; it's a straight completion model with `frequency_penalty`, `presence_penalty`, and `seed` for more classic sampling control. If your pipeline needs to dial reasoning depth up for hard problems and down for cheap ones, only Opus 4.6 gives you that lever.
When to pick each
Pick Opus 4.6 when correctness on code or multi-step agent tasks matters more than per-token cost — it's the only one of the two with agents-arena data at all, and it leads every models-arena category it appears in. Pick Mistral Large 3 2512 when you're running high volume, lower-stakes text generation and the 12.5x cost difference on a 10M/2M workload actually moves your budget. Both models run on OpenKey through one API key, billed at provider list price plus a flat 3% fee — so switching between them for a/b testing costs you nothing but the token bill itself.
Which model for which job
| Use case | Pick | Why |
|---|---|---|
| Autonomous coding agents | Claude Opus 4.6 | Only model with agents-arena data; ranks 3-4 across fullstack, mobileapps, webapps |
| High-volume text generation | Mistral Large 3 2512 | $8.00 vs $100.00 on a 10M-in/2M-out workload — 12.5x cheaper |
| UI component generation | Claude Opus 4.6 | Rank 3 in uicomponent (elo 1350, 64.5% win rate) vs Mistral's rank 59 |
| Long-document analysis (250K+ tokens) | Claude Opus 4.6 | 1M-token context vs Mistral's 262,144-token cap, a 3.81x difference |
| Budget-constrained prototyping | Mistral Large 3 2512 | $0.515/M input on OpenKey, open Apache 2.0 license, no reasoning overhead |
| Variable reasoning depth per request | Claude Opus 4.6 | Exposes reasoning effort levels (max/high/medium/low); Mistral has no reasoning parameter |
Questions
- How much more expensive is Claude Opus 4.6 than Mistral Large 3 2512?
- On input tokens it's exactly 10x more expensive ($5.00/M vs $0.50/M provider price). On a full workload of 10M input and 2M output tokens, Opus 4.6 costs $100.00 total against $8.00 for Mistral Large — a 12.5x gap once output pricing is factored in.
- Which model has a bigger context window?
- Claude Opus 4.6 supports 1,000,000 tokens of context versus Mistral Large 3 2512's 262,144 tokens, a 3.81x ratio. If you're processing large codebases or long documents in one pass, Opus 4.6's window gives you more headroom before you need to chunk input.
- Is Mistral Large 3 2512 good for coding?
- It's usable but not competitive with Opus 4.6. Mistral's artificial_analysis coding index is 20.1 and its best Design Arena coding rank is 56th (codecategories, elo 1191). Opus 4.6 ranks 3rd in the same category with elo 1342.
- Can I use both models with the same API key?
- Yes — both Claude Opus 4.6 and Mistral Large 3 2512 are available on OpenKey with one key across all 329 models. Pricing is provider list price plus a flat 3% fee, so Opus 4.6 comes to $5.15/M input and $25.75/M output, and Mistral Large comes to $0.515/M input and $1.545/M output.