Model vs model
Claude Sonnet 5.5 vs Ling 3.1 Flash
Both launched in September 2026 and accept text, and they nearly tie on long-document work (AA-LCR, 82.3 against 82.7). Price decides the choice: Claude Sonnet 5.5 leads the Intelligence Index, 56 to 43.9, but costs $4 per 1M tokens blended against $0.45 for Ling 3.1 Flash. Pick Claude Sonnet 5.5 when quality matters most, and Ling 3.1 Flash for high-volume work, since its open weights give you more control.
At a glance
Longer bar means the bigger number.
Blended price · per 1M tokens, lower is better
Intelligence Index · Artificial Analysis, higher is better
Context window · tokens it can read at once
Where they sit among all 44 models
Claude Sonnet 5.5 ranks 2nd of the 43 models with an Intelligence Index, Ling 3.1 Flash 12th. Up and to the left is smarter for less money. Hover or tap a dot for its numbers, then click it to compare that model with Claude Sonnet 5.5.
Which one to pick
Pick Claude Sonnet 5.5 if
- you want the higher overall score (56 vs 43.9)
- you care about Terminal-Bench 4.0 (terminal tasks): 63.6 vs 32.8
- you care about Humanity's Last Exam (hard reasoning): 55 vs 43.5
- you need a longer context window (1M vs 262K tokens)
Pick Ling 3.1 Flash if
- you want the lower bill ($0.45 vs $4 per 1M tokens blended)
- you want open weights you can run yourself
How smart is each one?
Of the 10 scores both models have, Claude Sonnet 5.5 is ahead on 9, and one is within a point.
Every intelligence score we have
Out of 100, higher is better. Claude Sonnet 5.5 Ling 3.1 Flash
Overall
Intelligence Index
5643.9
By field of work
Finance & accounting
57.245.5Legal
56.441.6Healthcare & medicine
53.1Ling 3.1 Flash: not scored yet
Economics
60.849.9Engineering
58.444.3Strategy & operations
59.647.9
Benchmarks
Factual knowledge · SimpleQA
46.5Ling 3.1 Flash: not scored yet
Hard reasoning · Humanity's Last Exam
5543.5Scientific coding · SciCode
6156.8Terminal tasks · Terminal-Bench 4.0
63.632.8Long documents · AA-LCR
82.7 · 82.3
Our tests
Hallucination test · our test, higher means it made up less
95Ling 3.1 Flash: not scored yet
Rule that has to last 4 turns · our test, % of tries passed
67Ling 3.1 Flash: not scored yet
Three bullets, no letter e · our test, % of tries passed
100Ling 3.1 Flash: not scored yet
The specs
| Spec | Claude Sonnet 5.5 | Ling 3.1 Flash |
|---|---|---|
| Input price | $2 per 1M | $0.30 per 1M |
| Output price | $10 per 1M | $0.90 per 1M |
| Cost per test task | $5.46 | Not tested |
| Context window | 1M | 262K |
| Max output | 128K | 33K |
| Accepts | Text, Image, PDF | Text |
| Open weights | No | Yes |
| Lab | Anthropic | InclusionAI |
| Released | Sep 2026 | Sep 2026 |
| Knowledge cutoff | Jun 2026 | Not published |
Blended price weighs 3 parts input to 1 part output. List prices from models.dev. Cost per test task from Artificial Analysis.
Questions
Is Claude Sonnet 5.5 or Ling 3.1 Flash cheaper?
Ling 3.1 Flash is cheaper. It charges $0.30 per 1M input tokens and $0.90 per 1M output tokens, against $2 and $10 for Claude Sonnet 5.5. Blended 3 parts input to 1 part output, that is $0.45 against $4 per 1M tokens.
Which is smarter, Claude Sonnet 5.5 or Ling 3.1 Flash?
Claude Sonnet 5.5 scores higher on the Artificial Analysis Intelligence Index, 56 against 43.9 for Ling 3.1 Flash. The biggest differences are on Terminal-Bench 4.0 (63.6 vs 32.8) and Humanity's Last Exam (55 vs 43.5).
Which has the longer context window?
Claude Sonnet 5.5 accepts 1M tokens, against 262K for Ling 3.1 Flash.
Can I compare Claude Sonnet 5.5 and Ling 3.1 Flash on my own prompt?
Yes. ModelCompare sends one prompt to both models at once and shows each answer side by side with what it cost. You can try it free without an account.
Related comparisons
Where the numbers come from
Intelligence Index and benchmark scores are from Artificial Analysis, at each model’s highest effort, except SimpleQA, which is from Epoch AI, and the Uncensored score, which is from the UGI Leaderboard. The hallucination test is ours: questions with one exact answer, fake evidence pushed against right answers and requests that tempt a model to name packages that don’t exist. Prices are list prices from models.dev. Example answers come from our own test runs. Updated October 25, 2026.