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Claude 4 Sonnet vs Claude 3.5 Sonnet
Which AI model is better in 2026? Compare Claude 4 Sonnet and Claude 3.5 Sonnet on benchmarks, pricing, speed, context window, and real-world fit.
Quick summary
Claude 4 Sonnet is currently the stronger overall pick for reasoning, coding, math, context, and speed. Claude 3.5 Sonnet stays competitive on several rows. Claude 3.5 Sonnet remains the budget pick at $6.00 vs $6.00 blended / 1M tokens.
Overall winner
Claude 4 Sonnet
Claude 4 Sonnet wins
- Reasoning
- Coding
- Math
- Context
- Speed
Claude 3.5 Sonnet wins
No clear category wins in our scorecard.
Want to compare different models?
Pick any two modelsClaude 4 Sonnet
The Anthropic sweet spot — Opus-class coding at a fraction of the price.
Claude 3.5 Sonnet
The model that made coding agents viable — still a top pick.
Claude 4 Sonnet vs Claude 3.5 Sonnet: overview
Claude 4 Sonnet (Anthropic) and Claude 3.5 Sonnet (Anthropic) are frequently compared by teams choosing an AI stack in 2026. Claude 4 Sonnet: The Anthropic sweet spot — Opus-class coding at a fraction of the price. Claude 3.5 Sonnet: The model that made coding agents viable — still a top pick. This Claude 4 Sonnet vs Claude 3.5 Sonnet comparison covers benchmarks, pricing, context window, speed, modalities, strengths, weaknesses, and who should pick which model.
Claude 4 Sonnet is proprietary with a 500k-token context window and a blended API price near $6.00 / 1M tokens (intelligence index 75/100). Claude 3.5 Sonnet is proprietary with 200k context at about $6.00 blended / 1M (intelligence 71/100). Those gaps drive most “Claude 4 Sonnet vs Claude 3.5 Sonnet” searches — quality versus cost, closed versus open, cloud versus self-host.
Where they differ most: Claude 4 Sonnet tends to lead on reasoning, coding, math, context, and speed. Choose Claude 4 Sonnet when you want the stronger overall profile on our scorecard; validate with your own evals before migrating production traffic.
Claude 4 Sonnet is often shortlisted for production coding tools, long-context rag, and tool use. Claude 3.5 Sonnet fits coding tasks, long-form writing, and agentic workflows. Scroll to pricing, real-world tasks, and the who-should-choose section for decision support.
People search “Claude 4 Sonnet vs Claude 3.5 Sonnet”, “which is better”, and “Claude 4 Sonnet vs Claude 3.5 Sonnet pricing” for the same reason: switching models is expensive if quality drops, and staying put is expensive if you overpay. Use the winner card for a fast answer, the head-to-head table for receipts, and the editorial verdict for a human recommendation. Claude 4 Sonnet currently ranks among competitive options from Anthropic; Claude 3.5 Sonnet is a hosted alternative from Anthropic. If API pricing is your main concern, start with the pricing section; for multimodal workloads, check vision/audio rows in technical differences; for agents and long documents, prioritize context and reasoning wins.
Head to head
Pricing comparison
API cost is often the deciding factor in Claude 4 Sonnet vs Claude 3.5 Sonnet for high-volume apps. Figures below use catalog list prices with a 3:1 input:output blend for monthly estimates. Cached input, batch, and realtime surcharges vary by provider — confirm on official docs.
| API cost | Claude 4 Sonnet | Claude 3.5 Sonnet |
|---|---|---|
| Input / 1M tokens | $3.00 | $3.00 |
| Output / 1M tokens | $15.00 | $15.00 |
| Blended (3:1) / 1M | $6.00 | $6.00 |
| Est. cost @ 1M blended tokens | $6.00 | $6.00 |
| Est. cost @ 10M blended tokens | $60.00 | $60.00 |
| Est. cost @ 100M blended tokens | $600.00 | $600.00 |
Cached input, batch API, and realtime surcharges are provider-specific and not always published in our catalog — verify on official pricing pages.
Benchmark showdown
Claude 4 Sonnet leads on MMLU, MMLU Pro, MATH, and HumanEval, indicating stronger coding and reasoning-oriented scores. Claude 3.5 Sonnet leads on GPQA. Claude 3.5 Sonnet remains attractive for production deployments on price. Raw benchmarks shortlist models — run task-specific evals before you switch.
Real-world performance
Beyond academic scores, here is how Claude 4 Sonnet vs Claude 3.5 Sonnet tends to split common product tasks based on catalog strengths, price, and modalities.
| Task | Winner |
|---|---|
| Coding | Claude 4 Sonnet |
| Blog writing | Claude 4 Sonnet |
| Research | Claude 4 Sonnet |
| Customer support | Claude 4 Sonnet |
| Cheap API / high volume | Claude 4 Sonnet |
| AI agents | Claude 4 Sonnet |
| Summarization | Claude 4 Sonnet |
| Translation | Claude 4 Sonnet |
| Vision / multimodal | Claude 4 Sonnet |
| Self-hosting / open weights | Claude 4 Sonnet |
Technical differences
| Feature | Claude 4 Sonnet | Claude 3.5 Sonnet |
|---|---|---|
| Provider | Anthropic | Anthropic |
| License | Proprietary | Proprietary |
| Pricing model | tokens | tokens |
| Context window | 500k tokens | 200k tokens |
| Max output | 16k tokens | 8k tokens |
| Vision input | Yes | Yes |
| Audio input | No | No |
| Text output | Yes | Yes |
| Image output | No | No |
| Video output | No | No |
| Audio output | No | No |
| Self-host friendly | No | No |
| Docs | Available | Available |
Strengths, weaknesses and best-for
- Best $/HumanEval ratio
- Fast
- 500k context
- Behind Opus on hardest reasoning
- Production coding tools
- Long-context RAG
- Tool use
- Excellent at code
- Strong writing
- Long context
- Superseded by Claude 4 Sonnet for new builds
- Coding tasks
- Long-form writing
- Agentic workflows
Who should choose which
Choose Claude 4 Sonnet if
- You need stronger reasoning, coding, or math quality
- You need a larger context window
- You care about faster token throughput
- Production coding tools
- Long-context RAG
Choose Claude 3.5 Sonnet if
- Coding tasks
- Long-form writing
Pros & cons
Claude 4 Sonnet
Pros
- Best $/HumanEval ratio
- Fast
- 500k context
Cons
- Behind Opus on hardest reasoning
Claude 3.5 Sonnet
Pros
- Excellent at code
- Strong writing
- Long context
Cons
- Superseded by Claude 4 Sonnet for new builds
Editorial verdict
Claude 4 Sonnet edges this matchup — with caveats
Claude 4 Sonnet is the better choice when you prioritize reasoning, coding, math, context, and speed. Claude 3.5 Sonnet stands out for specific workloads, making it a strong option when those dimensions matter more than raw leaderboard rank. If maximum measured performance matters, Claude 4 Sonnet wins this matchup. If your niche constraints matter more, Claude 3.5 Sonnet is difficult to beat. Always confirm with a bake-off on your real prompts before cutting over.
Still deciding? Read the full Claude 4 Sonnet review and Claude 3.5 Sonnet review, or open the full AI models table.
Claude 4 Sonnet vs Claude 3.5 Sonnet — frequently asked questions
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