Today I stumbled upon a LinkedIn post about their CursorBench 3.1, which I found very interesting.
With Sonnet 5 out and Fable 5 available again, I used the benchmark to compare all three families by budget and target use.
I’ll start from the conclusions, and data / graphs will follow.
Three cost/score bands
The data splits cleanly into three regimes depending on the score you actually need:
| Band | Target score | Winner | Cost | Why |
|---|---|---|---|---|
| Budget | ≤55% | Sonnet 5 (Low–Medium) | $1.46–$2.57 | Cheapest points on the chart |
| Mid | 55–58% | Opus 4.8 (High) | $4.41 | Matches Sonnet 5 Extra High’s score ($5.23) for less |
| High | 60%+ | Fable 5 (Low) | $5.70 | Beats every Opus 4.8/Sonnet 5 tier above 60%, on cost and score |
Past ~65%, only Fable 5 gets there at all.
Cost vs. score graph
Fable 5
Opus 4.8
Sonnet 5
Tokens vs. score graph
Fable 5
Opus 4.8
Sonnet 5
Takeaways
- Sonnet 5 Medium and Opus 4.8 Low are roughly equivalent on cost and tokens. Sonnet’s slight score edge makes it the pick for everyday work.
- Sonnet 5 High edges out Opus 4.8 Medium, but Opus 4.8 High wins that same score bracket outright. You may never want to use Sonnet 5 Extra High.
- Need something more than Opus 4.8 High? Just switch to Fable 5 Low. Considering the output tokens you may also prefer it to Opus 4.8 Max.
In short:
- Quick, low-stakes edits → Sonnet 5 Low/Medium.
- Everyday feature work → Opus 4.8 High.
- Need to go smarter? Fable 5 Low is the deal.
Data pulled from a screenshot of the CursorBench 3.1 leaderboard; the live page may have since updated with more models or revised numbers.
Raw data
| Model | Tier | Score % | Cost/task | Tokens/task |
|---|---|---|---|---|
| Fable 5 | Max | 72.9 | $18.02 | 63,842 |
| Fable 5 | Extra High | 72.0 | $13.74 | 48,754 |
| Fable 5 | High | 70.6 | $10.81 | 37,173 |
| Fable 5 | Medium | 69.8 | $8.27 | 28,507 |
| Fable 5 | Low | 64.2 | $5.70 | 18,882 |
| Opus 4.8 | Max | 63.8 | $7.59 | 77,370 |
| Opus 4.8 | Extra High | 62.1 | $6.14 | 55,622 |
| Opus 4.8 | High | 58.4 | $4.41 | 36,788 |
| Opus 4.8 | Medium | 56.6 | $3.83 | 31,684 |
| Opus 4.8 | Low | 54.3 | $2.93 | 22,726 |
| Sonnet 5 | Max | 61.2 | $6.87 | 93,485 |
| Sonnet 5 | Extra High | 58.4 | $5.23 | 58,228 |
| Sonnet 5 | High | 57.0 | $3.74 | 41,735 |
| Sonnet 5 | Medium | 54.9 | $2.57 | 27,469 |
| Sonnet 5 | Low | 47.7 | $1.46 | 17,028 |