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Claude 3.5 Haiku vs Claude Mythos 5.1

Claude Mythos 5.1 leads the LLM Stats Score 45.1 to 5.3. Claude 3.5 Haiku is 12.5x cheaper per token.

Anthropic · Anthropic · Updated for 2026

Which is better?

Claude Mythos 5.1 leads the overall LLM Stats Score 45.1 to 5.3, ranking #31 overall.

On price, Claude 3.5 Haiku is roughly 12.5x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.

Claude Mythos 5.1 also accepts a larger context window (1,000,000 input tokens), making it the stronger choice for long documents and large codebases.

Based on current LLM Stats indexes, shared benchmarks, pricing, and model metadata for 2026.

Choose Claude 3.5 Haiku

  • cost matters — it's about 12.5x cheaper per token

Choose Claude Mythos 5.1

  • overall performance matters — it scores 45.1 and ranks #31 on LLM Stats
  • your work emphasizes reasoning and coding — it leads those capability indexes
  • you process long inputs — it offers a 1,000,000 token context window
  • you want the most recent training data — it shipped Sep 2026

At a glance

The differences that matter most.

Claude 3.5 Haiku
Anthropic
Claude Mythos 5.1
Anthropic
Core performance indexes
LLM Stats Score
5.3
#296
45.1
#31
Reasoning
5.4
#292
44.4
#34
Coding
4.2
#209
37.5
#17
Cost, coverage & limits
Benchmark wins
—
—
Input price
$0.80 / M
$10.00 / M
Output price
$4.00 / M
$50.00 / M
Context window
200,000
1,000,000

Individual benchmarks

9 reported for Claude 3.5 Haiku · 1 for Claude Mythos 5.1

No common benchmarks found

Claude 3.5 Haiku and Claude Mythos 5.1don't have any common benchmark datasets to compare. They may have been evaluated on different testing suites.

Human preference

Blind head-to-head votes and playground preference scores

Pricing Analysis

Price comparison per million tokens

Claude 3.5 Haiku costs less

For input processing, Claude 3.5 Haiku ($0.80/1M tokens) is 12.5x cheaper than Claude Mythos 5.1 ($10.00/1M tokens).

For output processing, Claude 3.5 Haiku ($4.00/1M tokens) is 12.5x cheaper than Claude Mythos 5.1 ($50.00/1M tokens).

In conclusion, Claude Mythos 5.1 is more expensive than Claude 3.5 Haiku.*

* Using a 3:1 ratio of input to output tokens

Lowest available price from all providers
Tue Sep 08 2026 • llm-stats.com
Anthropic
Claude 3.5 Haiku
Input tokens$0.80
Output tokens$4.00
Best providerAWS Bedrock
Anthropic
Claude Mythos 5.1
Input tokens$10.00
Output tokens$50.00
Best providerAnthropic
Notice missing or incorrect data?Start an Issue→

Context Window

Maximum input and output token capacity

Claude Mythos 5.1 accepts 1,000,000 input tokens compared to Claude 3.5 Haiku's 200,000 tokens. Claude 3.5 Haiku can generate longer responses up to 200,000 tokens, while Claude Mythos 5.1 is limited to 128,000 tokens.

Anthropic
Claude 3.5 Haiku
Input200,000 tokens
Output200,000 tokens
Anthropic
Claude Mythos 5.1
Input1,000,000 tokens
Output128,000 tokens
Tue Sep 08 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

Claude Mythos 5.1 supports multimodal inputs, whereas Claude 3.5 Haiku does not.

Claude Mythos 5.1 can handle both text and other forms of data like images, making it suitable for multimodal applications.

Claude 3.5 Haiku

Text
Images
Audio
Video

Claude Mythos 5.1

Text
Images
Audio
Video

License

Usage and distribution terms

Both models are licensed under proprietary licenses.

Both models have usage restrictions defined by their respective organizations.

Claude 3.5 Haiku

Proprietary

Closed source

Claude Mythos 5.1

Proprietary

Closed source

Release Timeline

When each model was launched

Claude 3.5 Haiku was released on 2024-10-22, while Claude Mythos 5.1 was released on 2026-09-01.

Claude Mythos 5.1 is 23 months newer than Claude 3.5 Haiku.

Claude 3.5 Haiku

Oct 22, 2024

1.9 years ago

Claude Mythos 5.1

Sep 1, 2026

1 weeks ago

1.9yr newer

Knowledge Cutoff

When training data ends

Neither model specifies a knowledge cutoff date.

Unable to compare the recency of their training data.

No cutoff dates available

Provider Availability

Claude 3.5 Haiku is available from Bedrock, Google, Anthropic. Claude Mythos 5.1 is available from Anthropic.

Claude 3.5 Haiku

bedrock logo
AWS Bedrock
Input Price:Input: $0.80/1MOutput Price:Output: $4.00/1M
google logo
Google
Input Price:Input: $0.80/1MOutput Price:Output: $4.00/1M
anthropic logo
Anthropic
Input Price:Input: $1.00/1MOutput Price:Output: $5.00/1M

Claude Mythos 5.1

anthropic logo
Anthropic
Input Price:Input: $10.00/1MOutput Price:Output: $50.00/1M
* Prices shown are per million tokens

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion→

Judge for yourself.

Run your own prompts against Claude 3.5 Haiku and Claude Mythos 5.1 side-by-side, then vote on the output you prefer.

Claude 3.5 Haiku
✓ Preferred
Claude Mythos 5.1
Open in Playground

FAQ

Common questions about Claude 3.5 Haiku vs Claude Mythos 5.1.

Which is better, Claude 3.5 Haiku or Claude Mythos 5.1?

Claude Mythos 5.1 leads the LLM Stats Score 45.1 to 5.3. Claude 3.5 Haiku is made by Anthropic and Claude Mythos 5.1 is made by Anthropic. The best choice depends on your use case — compare their capability indexes, individual benchmarks, pricing, and limits above.

How does Claude 3.5 Haiku compare to Claude Mythos 5.1 in benchmarks?

Claude 3.5 Haiku scores HumanEval: 88.1%, MGSM: 85.6%, DROP: 83.1%, MATH: 69.4%, MMLU-Pro: 65.0%. Claude Mythos 5.1 scores Terminal-Bench 4.0: 60.9%.

Is Claude 3.5 Haiku cheaper than Claude Mythos 5.1?

Claude 3.5 Haiku is 12.5x cheaper for input tokens. Claude 3.5 Haiku costs $0.80/M input and $4.00/M output via bedrock. Claude Mythos 5.1 costs $10.00/M input and $50.00/M output via anthropic.

What are the context window sizes for Claude 3.5 Haiku and Claude Mythos 5.1?

Claude 3.5 Haiku supports 200K tokens and Claude Mythos 5.1 supports 1.0M tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

What are the main differences between Claude 3.5 Haiku and Claude Mythos 5.1?

Key differences include LLM Stats Score (5.3 vs 45.1), context window (200K vs 1.0M), input pricing ($0.80 vs $10.00/M), multimodal support (no vs yes). See the full comparison above for benchmark-by-benchmark results.

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