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Claude Mythos 5.1 vs GPT-3.5 Turbo

Claude Mythos 5.1 leads the LLM Stats Score 45.1 to -9.3. GPT-3.5 Turbo is 26.7x cheaper per token.

Anthropic · OpenAI · Updated for 2026

Which is better?

Claude Mythos 5.1 leads the overall LLM Stats Score 45.1 to -9.3, ranking #31 overall.

On price, GPT-3.5 Turbo is roughly 26.7x 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 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

Choose GPT-3.5 Turbo

  • cost matters — it's about 26.7x cheaper per token

At a glance

The differences that matter most.

Core performance indexes
45.1
#31
-9.3
#362
44.4
#34
-8.6
#355
37.5
#17
-4.5
#256
Cost, coverage & limits
Benchmark wins
Input price
$10.00 / M
$0.50 / M
Output price
$50.00 / M
$1.50 / M
Context window
1,000,000
16,385

Individual benchmarks

1 reported for Claude Mythos 5.1 · 8 for GPT-3.5 Turbo

No common benchmarks found

Claude Mythos 5.1 and GPT-3.5 Turbodon'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

GPT-3.5 Turbo costs less

For input processing, Claude Mythos 5.1 ($10.00/1M tokens) is 20.0x more expensive than GPT-3.5 Turbo ($0.50/1M tokens).

For output processing, Claude Mythos 5.1 ($50.00/1M tokens) is 33.3x more expensive than GPT-3.5 Turbo ($1.50/1M tokens).

In conclusion, Claude Mythos 5.1 is more expensive than GPT-3.5 Turbo.*

* 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 Mythos 5.1
Input tokens$10.00
Output tokens$50.00
Best providerAnthropic
OpenAI
GPT-3.5 Turbo
Input tokens$0.50
Output tokens$1.50
Best providerAzure
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 GPT-3.5 Turbo's 16,385 tokens. Claude Mythos 5.1 can generate longer responses up to 128,000 tokens, while GPT-3.5 Turbo is limited to 4,096 tokens.

Anthropic
Claude Mythos 5.1
Input1,000,000 tokens
Output128,000 tokens
OpenAI
GPT-3.5 Turbo
Input16,385 tokens
Output4,096 tokens
Tue Sep 08 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

Claude Mythos 5.1 supports multimodal inputs, whereas GPT-3.5 Turbo does not.

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

Claude Mythos 5.1

Text
Images
Audio
Video

GPT-3.5 Turbo

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 Mythos 5.1

Proprietary

Closed source

GPT-3.5 Turbo

Proprietary

Closed source

Release Timeline

When each model was launched

Claude Mythos 5.1 was released on 2026-09-01, while GPT-3.5 Turbo was released on 2023-03-21.

Claude Mythos 5.1 is 42 months newer than GPT-3.5 Turbo.

Claude Mythos 5.1

Sep 1, 2026

1 weeks ago

3.5yr newer
GPT-3.5 Turbo

Mar 21, 2023

3.5 years ago

Knowledge Cutoff

When training data ends

GPT-3.5 Turbo has a documented knowledge cutoff of 2021-09-30, while Claude Mythos 5.1's cutoff date is not specified.

We can confirm GPT-3.5 Turbo's training data extends to 2021-09-30, but cannot make a direct comparison without Claude Mythos 5.1's cutoff date.

Claude Mythos 5.1

GPT-3.5 Turbo

Sep 2021

Provider Availability

Claude Mythos 5.1 is available from Anthropic. GPT-3.5 Turbo is available from Azure, OpenAI.

Claude Mythos 5.1

anthropic logo
Anthropic
Input Price:Input: $10.00/1MOutput Price:Output: $50.00/1M

GPT-3.5 Turbo

azure logo
Azure
Input Price:Input: $0.50/1MOutput Price:Output: $1.50/1M
openai logo
OpenAI
Input Price:Input: $0.50/1MOutput Price:Output: $1.50/1M
* 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 Mythos 5.1 and GPT-3.5 Turbo side-by-side, then vote on the output you prefer.

Claude Mythos 5.1
✓ Preferred
GPT-3.5 Turbo
Open in Playground

FAQ

Common questions about Claude Mythos 5.1 vs GPT-3.5 Turbo.

Which is better, Claude Mythos 5.1 or GPT-3.5 Turbo?

Claude Mythos 5.1 leads the LLM Stats Score 45.1 to -9.3. Claude Mythos 5.1 is made by Anthropic and GPT-3.5 Turbo is made by OpenAI. The best choice depends on your use case — compare their capability indexes, individual benchmarks, pricing, and limits above.

How does Claude Mythos 5.1 compare to GPT-3.5 Turbo in benchmarks?

Claude Mythos 5.1 scores Terminal-Bench 4.0: 60.9%. GPT-3.5 Turbo scores DROP: 70.2%, MMLU: 69.8%, HumanEval: 68.0%, MGSM: 56.3%, MATH: 43.1%.

Is Claude Mythos 5.1 cheaper than GPT-3.5 Turbo?

GPT-3.5 Turbo is 20.0x cheaper for input tokens. Claude Mythos 5.1 costs $10.00/M input and $50.00/M output via anthropic. GPT-3.5 Turbo costs $0.50/M input and $1.50/M output via azure.

What are the context window sizes for Claude Mythos 5.1 and GPT-3.5 Turbo?

Claude Mythos 5.1 supports 1.0M tokens and GPT-3.5 Turbo supports 16K tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

What are the main differences between Claude Mythos 5.1 and GPT-3.5 Turbo?

Key differences include LLM Stats Score (45.1 vs -9.3), context window (1.0M vs 16K), input pricing ($10.00 vs $0.50/M), multimodal support (yes vs no). See the full comparison above for benchmark-by-benchmark results.

Who makes Claude Mythos 5.1 and GPT-3.5 Turbo?

Claude Mythos 5.1 is developed by Anthropic and GPT-3.5 Turbo is developed by OpenAI.