What is the difference between Llama 3.1 405B and Qwen3.5 Plus 2026-04-20?

Llama 3.1 405B is developed by Meta AI while Qwen3.5 Plus 2026-04-20 is developed by Qwen. Llama 3.1 405B has a 128K token context window vs Qwen3.5 Plus 2026-04-20's 1.0M. You can compare their actual outputs across 12 challenges on Rival to see how they differ in practice.

Which is better, Llama 3.1 405B or Qwen3.5 Plus 2026-04-20?

It depends on your use case. Llama 3.1 405B and Qwen3.5 Plus 2026-04-20 each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 12 challenges so you can judge which fits your needs best.

How much does Llama 3.1 405B cost compared to Qwen3.5 Plus 2026-04-20?

Llama 3.1 405B costs $2.7/M input tokens and Qwen3.5 Plus 2026-04-20 costs $0.4/M input tokens. Qwen3.5 Plus 2026-04-20 is $2.30/M cheaper per input. Check their side-by-side outputs on Rival to see if the price difference is justified by quality.

How can I compare Llama 3.1 405B and Qwen3.5 Plus 2026-04-20 on Rival?

This page shows a side-by-side comparison of Llama 3.1 405B and Qwen3.5 Plus 2026-04-20 across shared challenges. You can vote on which model produced the better output in a blind duel. Browsing and voting are free. No account is needed to look; signing in only saves your votes and likes.

Updated Apr 2026

Llama 3.1 405BvsQwen3.5 Plus 2026-04-20

Qwen3.5 Plus 2026-04-20 is cheaper than Llama 3.1 405B at $0.4/M vs $2.7/M input tokens.

Llama 3.1 405B and Qwen3.5 Plus 2026-04-20 compared across 12 shared prompts
Spec	Llama 3.1 405B	Qwen3.5 Plus 2026-04-20
Input price	$2.7/M tokens	$0.4/M tokens
Output price	$3.1/M tokens	$2.4/M tokens
Context window	128K tokens	1.0M tokens
Weights	Open	Open
Free API (OpenRouter)	No	No
Released	Jul 2024	Apr 2026

Our Verdict

Llama 3.1 405B

Qwen3.5 Plus 2026-04-20

Not enough votes to call it. On the specs, nothing separates them.

Too close to call

Reviewing agent-written code?See a Brief PR report

API pricing

Cost per 1M tokens

Llama 3.1 405B

Input

$2.70

Output

$3.10

Qwen3.5 Plus 2026-04-20

Input

$0.40

6.8× cheaper

Output

$2.40

1.3× cheaper

Qwen3.5 Plus 2026-04-20 is cheaper on both: 6.8× input, 1.3× output.

Where to run it

1 host

Llama 3.1 405B

No hosts listed on OpenRouter.

Qwen3.5 Plus 2026-04-201 host

HostInOutContextUptime

Alibaba Cloud$0.30 in$1.80 out1M100% up

Per million tokens. Prices and uptime via OpenRouter, checked 16 Sep 2026.

Writing DNA

Style Comparison

Similarity

53%

Qwen3.5 Plus 2026-04-20 uses 440.8x more bold

Llama 3.1 405B

Qwen3.5 Plus 2026-04-20

55%Vocabulary59%

15wSentence Length15w

0.41Hedging0.28

0.0Bold4.4

1.9Lists2.5

0.03Emoji1.53

0.00Headings0.76

0.16Transitions0.04

Based on 5 + 27 text responses

Research

What we learned reading every model

FAQ

Common questions

Keep exploring

More comparisons

Cost per 1M tokens

1 host

Style Comparison

What we learned reading every model

Common questions

What is the difference between Llama 3.1 405B and Qwen3.5 Plus 2026-04-20?

Which is better, Llama 3.1 405B or Qwen3.5 Plus 2026-04-20?

How much does Llama 3.1 405B cost compared to Qwen3.5 Plus 2026-04-20?

How can I compare Llama 3.1 405B and Qwen3.5 Plus 2026-04-20 on Rival?

More comparisons

Against the newest arrivals

Same lab, same size, long tail

Model pages

Cost per 1M tokens

1 host

Style Comparison

What we learned reading every model

Common questions

What is the difference between Llama 3.1 405B and Qwen3.5 Plus 2026-04-20?

Which is better, Llama 3.1 405B or Qwen3.5 Plus 2026-04-20?

How much does Llama 3.1 405B cost compared to Qwen3.5 Plus 2026-04-20?

How can I compare Llama 3.1 405B and Qwen3.5 Plus 2026-04-20 on Rival?

More comparisons

Against the newest arrivals

Same lab, same size, long tail

Model pages