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Claude Sonnet 5.5 vs Ling 3.1 Flash

Claude Sonnet 5.5 has the stronger public benchmark scores. Ling 3.1 Flash costs 89% less for the same work.

Claude Sonnet 5.5

by Anthropic · #2 of 67 overall

Coming soon · price at launch
Context
1M
Input / 1M
$2.00
Output / 1M
$10.00

Ling 3.1 Flash

by inclusionAI

Coming soon · price at launch
Context
256K
Input / 1M
$0.30
Output / 1M
$0.90

Better overall

Claude Sonnet 5.5

Grade 91.2 vs —

Cheaper

Ling 3.1 Flash

89% less, $0.45 vs $4.00 blended

Larger context

Claude Sonnet 5.5

1M vs 256K tokens

SWE-Bench Pro

Claude Sonnet 5.5

81.3% vs 68.7%

Head to head

Public benchmarks. Longer is better; each value links to its source.

LMArena TextElo-style rating · LMArena (CC BY 4.0) · Oct 15, 2026
Claude Sonnet 5.5Claude Sonnet 5.5: 1,475
Ling 3.1 FlashLing 3.1 Flash: —
LMArena WebDevElo-style rating · LMArena (CC BY 4.0) · Oct 13, 2026
Claude Sonnet 5.5Claude Sonnet 5.5: 1,774
Ling 3.1 FlashLing 3.1 Flash: —
LMArena CodingElo-style rating · LMArena (CC BY 4.0) · Oct 15, 2026
Claude Sonnet 5.5Claude Sonnet 5.5: 1,530
Ling 3.1 FlashLing 3.1 Flash: —
SWE-Bench Pro% of tasks resolved · Scale AI SWE-Bench Pro · Oct 13, 2026 · reference
Terminal-Bench 4.0% of tasks passed · Terminal-Bench · Oct 13, 2026 · reference
Claude Sonnet 5.5Claude Sonnet 5.5: 70.6%v
Ling 3.1 FlashLing 3.1 Flash: 46%v
Terminal-Bench 2.1% of tasks passed · Terminal-Bench · Oct 13, 2026 · reference
Claude Sonnet 5.5Claude Sonnet 5.5: —

Claude Sonnet 5.5Ling 3.1 Flashv = reported by the model’s maker. — = no public score yet. Arena bars span the range across every model we grade.

What it costs you

Drag to match your monthly usage.

Claude Sonnet 5.5$800 /month
Ling 3.1 Flash$96.00 /month

Ling 3.1 Flash saves you $704 a month at this usage, $8,448 a year.

At a glance

AttributeClaude Sonnet 5.5Ling 3.1 Flash
Made byAnthropicinclusionAI
AvailabilityComing soonComing soon
Overall gradeExcellent · 91.2Not rated
Overall rank#2 of 67Not ranked
Input price$2.00 per 1M$0.30 per 1M
Output price$10.00 per 1M$0.90 per 1M
Context window1,000,000 tokens262,144 tokens
Reasoning levelsYesNo
Reads imagesYesNo
Model IDclaude-sonnet-5-5ling-3.1-flash

Try both with one key

Same endpoint, same key, both hosted in the USA. Change one word to switch models, in Claude Code, Cursor, Cline or your own code.

Get your API key
# Ask either model the same thing
curl https://fullsendai.com/v1/chat/completions \
  -H "Authorization: Bearer $FULLSEND_API_KEY" \
  -d '{"model": "claude-sonnet-5-5", "messages": [...]}'

# …then swap one word
  -d '{"model": "ling-3.1-flash", "messages": [...]}'

Questions

Is Claude Sonnet 5.5 or Ling 3.1 Flash better?

One of them doesn’t have enough public benchmark scores to be graded yet; compare the benchmarks both have above.

Which is cheaper, Claude Sonnet 5.5 or Ling 3.1 Flash?

Ling 3.1 Flash: $0.30 in and $0.90 out per million tokens, against $2.00 and $10.00 through FullsendAI.

Which has the larger context window?

Claude Sonnet 5.5, with 1,000,000 tokens.

Can I use both with one API key?

Yes, once they launch: both are coming soon, at the prices shown, and both will use the same FullsendAI key.

Model rankingsAll benchmarksCompare other models

Scores: LMArena (CC BY 4.0), Scale AI SWE-Bench Pro, Terminal-Bench, and model makers’ published results where marked v. Prices are FullsendAI’s, per million tokens. Data as of Oct 28, 2026.