Claude Sonnet 5 vs MiniMax M3
Claude Sonnet 5 and MiniMax M3 both target coding and agentic workloads with near-identical context windows (1M vs 1.05M tokens), but they sit at opposite ends of the price-performance curve. Sonnet 5 leads on Artificial Analysis intelligence, coding, and agentic indices; M3 leads on cost by a wide margin and adds video input support Sonnet 5 doesn't have. Both are callable through OpenKey with a single API key at provider list price plus a flat 3% fee — no separate contracts needed.
Spec vs spec
| Spec | Claude Sonnet 5 | MiniMax M3 |
|---|---|---|
| Context window | 1M | 1.0M |
| Max output | 128K | 512K |
| Input modalities | text, image, file | text, image, video |
| Output modalities | text | text |
| Released | Jun 30, 2026 | May 31, 2026 |
| Reasoning | optional | optional |
Pricing
Per 1M tokens. Provider price plus the flat 3% fee — the sum is what you pay.
anthropic/claude-sonnet-5
Input · 1M tokens
$2.00 + 3%$2.06
Output · 1M tokens
$10.00 + 3%$10.30
Cache read · 1M tokens
$0.200 + 3%$0.206
Cache write · 1M tokens
$2.50 + 3%$2.58
FEE — FLAT, EVERY MODEL3%
minimax/minimax-m3
Input · 1M tokens
$0.300 + 3%$0.309
Output · 1M tokens
$1.20 + 3%$1.24
Cache read · 1M tokens
$0.060 + 3%$0.062
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-sonnet-5
$41.20
$40.00 provider + 3%
minimax/minimax-m3Cheaper
$5.56
$5.40 provider + 3%
Pricing math on a real workload
For a 10M input / 2M output token job, Claude Sonnet 5 costs $40.00 at OpenKey pricing (provider price $2.00/$10.00 per M tokens x 1.03 = $2.06/$10.30 per M). MiniMax M3 costs $5.40 for the same workload (provider price $0.30/$1.20 per M x 1.03 = $0.309/$1.236 per M). That's a 6.67x gap on input pricing alone. If you're running batch jobs, evals, or high-frequency agent loops, that difference compounds fast — a week of Sonnet 5 usage at this rate costs what a month of M3 usage costs.
Coding and agentic performance
On Artificial Analysis benchmarks, Claude Sonnet 5 scores 71.5 on the coding index and 46.7 on the agentic index, versus M3's 58.6 and 35.4. Sonnet 5's intelligence index (53.4) also beats M3's (44.4). MiniMax M3 has its own Design Arena results across coding-adjacent categories — codecategories (elo 1306, rank 13), svg (elo 1250, rank 13), dataviz (elo 1295, rank 11) — showing it's competitive in generative UI and code-adjacent tasks even without a direct Sonnet 5 comparison point there. For pure coding accuracy, Sonnet 5 is ahead by a clear margin.
Context and modality differences
Context windows are nearly identical: Sonnet 5 at 1,000,000 tokens, M3 at 1,048,576 tokens — a 0.95 ratio, effectively a wash for long-document work. Max output differs a lot more: Sonnet 5 caps at 128,000 tokens, M3 at 512,000 tokens, so M3 has more room for long-form generation in a single call. On modality, Sonnet 5 accepts text, image, and file input; M3 accepts text, image, and video, making it the pick if your pipeline needs video understanding.
When to pick each
Pick Claude Sonnet 5 when output quality on coding and agentic tasks drives your decision and cost per call is secondary — client-facing code generation, complex multi-step agents, or anything where a wrong answer is expensive. Pick MiniMax M3 when you're running high-volume batch work, need video input, or need long single-response output (512K tokens) and can accept a lower intelligence ceiling. Both support tool calling and structured outputs, so tooling compatibility isn't a differentiator here.
Which model for which job
| Use case | Pick | Why |
|---|---|---|
| High-volume coding agent pipeline | MiniMax M3 | 6.67x cheaper input tokens keeps per-run cost down at scale |
| Complex, high-stakes code generation | Claude Sonnet 5 | 71.5 coding index vs 58.6 gives a meaningful accuracy edge |
| Video-input agent tasks | MiniMax M3 | Only M3 accepts video as an input modality |
| Long single-response generation | MiniMax M3 | 512,000 max output tokens vs Sonnet 5's 128,000 |
| Autonomous multi-step agents | Claude Sonnet 5 | Agentic index of 46.7 vs M3's 35.4 |
| Budget-capped evaluation or batch jobs | MiniMax M3 | $5.40 vs $40.00 for a 10M-in/2M-out workload |
Questions
- Which model is cheaper for large workloads?
- MiniMax M3, by a lot. A 10M input / 2M output token job costs $5.40 on M3 versus $40.00 on Claude Sonnet 5 — a 6.67x gap driven by M3's $0.309/M input price against Sonnet 5's $2.06/M on OpenKey.
- Which model has the bigger context window?
- MiniMax M3, marginally. It supports 1,048,576 tokens versus Sonnet 5's 1,000,000 — a 0.95 context ratio, so in practice they're close enough that context size shouldn't drive your choice.
- Which model is better at coding?
- Claude Sonnet 5. Its Artificial Analysis coding index is 71.5 versus MiniMax M3's 58.6, and its agentic index (46.7 vs 35.4) also leads, making it the stronger choice for coding-heavy agent workflows.
- Can I switch between these two without changing my integration?
- Yes — both models run on OpenKey under one API key, billed at provider list price plus a flat 3% fee, so swapping the model ID in your request is the only change needed.