Quick answer. If you want the highest code quality and work across large codebases, use Claude Fable 5 (1M context, 95% SWE-bench). If you ship high volume and care about cost, use Claude Sonnet 4.6. On a tight budget, DeepSeek V3 gives near-frontier coding at a fraction of the price.
SWE-bench Verified: independent vs vendor-reported
SWE-bench Verified measures whether a model can resolve real GitHub issues. We show both the lab's own reported figure and the independent Scale SEAL number, because they often differ — and the gap matters.
| Model | Vendor-reported | Scale SEAL (independent) | Our task score |
|---|---|---|---|
| Claude Fable 5 | 80.3% | 95% | 97 |
| Claude Opus 4.8 | 88.6% | 86% | 91 |
| GPT-5.5 | 87% | 84% | 95 |
| Claude Sonnet 4.6 | 82% | 80% | 89 |
| DeepSeek V3 | 79% | 74% | 85 |
| GPT-4o | 54% | 51% | 84 |
Vendor figures from provider announcements; independent figures from the Scale SEAL leaderboard. Where a vendor's headline number diverges from independent testing, the independent number is the more reliable guide for real-world work.
Cost per benchmark point
The best model is not always the right one. Here is what each leading coding model costs and what you get for it.
| Model | Input $/M | Output $/M | Context | Best use |
|---|---|---|---|---|
| Claude Fable 5 | $10.00 | $50.00 | 1M | Highest quality, large codebases |
| Claude Sonnet 4.6 | $3.00 | $15.00 | 200k | High-volume daily driver |
| DeepSeek V3 | $0.27 | $1.10 | 128k | Budget, non-sensitive code |
| Claude Haiku 4.5 | $0.25 | $1.00 | 200k | Cheap + compliant subagents |
| GPT-5.4 | $2.50 | $15.00 | 128k | All-round with widest tooling |
Model your real monthly cost → using your own token volume in the calculator.
Who each model is best for
Choose Claude Fable 5 if…
- You work across whole codebases and need 1M context
- Code quality matters more than per-token cost
- You run agentic, multi-step coding tasks
Avoid it if…
- You are cost-constrained at high volume
- You only need simple autocomplete or boilerplate
- You need the absolute fastest response times
Decision matrix
| If you need… | Choose | Why |
|---|---|---|
| Highest code quality | Claude Fable 5 | 95% SWE-bench, 1M context |
| Best daily cost-performance | Claude Sonnet 4.6 | Strong coding at $3/$15 per M |
| Lowest cost | DeepSeek V3 | Near-frontier at $0.27/$1.10 |
| Cheap + GDPR/HIPAA | Claude Haiku 4.5 | $0.25/$1.00, full compliance |
| Widest IDE/tool support | GPT-5.4 | Largest integration ecosystem |
| Self-hosted / air-gapped | Llama 4 | Open weights, run on your own hardware |
What changed in June 2026
- Claude Fable 5's independent Scale SEAL SWE-bench result (95%) opened a clear lead over the field for agentic coding.
- DeepSeek V3 pricing held at $0.27/$1.10 per million tokens, keeping it the budget benchmark.
- GPT-5.4 became OpenAI's best-value coding flagship, displacing GPT-4o for most code work.
Not sure which fits your stack? Use the match engine — set your cost priority and privacy needs and get a tailored recommendation in seconds.