The AI arena is free today

Open Superagent

GPT-5 High vs Seed 1.8

GPT-5 High and Seed 1.8 are closely matched at 34.1 and 34.2 on the LLM Stats Score. Seed 1.8 is 5.0x cheaper per token.

OpenAI · ByteDance · Updated for 2026

Which is better?

GPT-5 High and Seed 1.8 are closely matched on the overall LLM Stats Score at 34.1 and 34.2.

In the 1 individual benchmarks reported for both models, GPT-5 High wins 1; this is a narrower head-to-head signal than the composite indexes.

On price, Seed 1.8 is roughly 5.0x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.

GPT-5 High also accepts a larger context window (400,000 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 GPT-5 High

  • you value its reported benchmark strengths — it wins 1 of 1 exact shared results
  • you process long inputs — it offers a 400,000 token context window

Choose Seed 1.8

  • cost matters — it's about 5.0x cheaper per token
  • you want the most recent training data — it shipped Feb 2026

At a glance

The differences that matter most.

Core performance indexes
34.1
#92
34.2
#91
33.0
#98
33.5
#93
Cost, coverage & limits
Benchmark wins
1 of 1
0 of 1
Input price
$1.25 / M
$0.25 / M
Output price
$10.00 / M
$2.00 / M
Context window
400,000
256,000

Individual benchmarks

2 reported for GPT-5 High · 57 for Seed 1.8

1 shared

GPT-5 High outperforms in 1 benchmarks (AIME 2025), while Seed 1.8 is better at 0 benchmarks.

GPT-5 High significantly outperforms across most benchmarks.

Wed Sep 09 2026 • llm-stats.com

Human preference

Blind head-to-head votes and playground preference scores

Pricing Analysis

Price comparison per million tokens

Seed 1.8 costs less

For input processing, GPT-5 High ($1.25/1M tokens) is 5.0x more expensive than Seed 1.8 ($0.25/1M tokens).

For output processing, GPT-5 High ($10.00/1M tokens) is 5.0x more expensive than Seed 1.8 ($2.00/1M tokens).

In conclusion, GPT-5 High is more expensive than Seed 1.8.*

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

Lowest available price from all providers
Wed Sep 09 2026 • llm-stats.com
OpenAI
GPT-5 High
Input tokens$1.25
Output tokens$10.00
Best providerOpenAI
ByteDance
Seed 1.8
Input tokens$0.25
Output tokens$2.00
Best providerDeepinfra
Notice missing or incorrect data?Start an Issue

Context Window

Maximum input and output token capacity

GPT-5 High accepts 400,000 input tokens compared to Seed 1.8's 256,000 tokens. Seed 1.8 can generate longer responses up to 256,000 tokens, while GPT-5 High is limited to 128,000 tokens.

OpenAI
GPT-5 High
Input400,000 tokens
Output128,000 tokens
ByteDance
Seed 1.8
Input256,000 tokens
Output256,000 tokens
Wed Sep 09 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

Both GPT-5 High and Seed 1.8 support multimodal inputs.

They are both capable of processing various types of data, offering versatility in application.

GPT-5 High

Text
Images
Audio
Video

Seed 1.8

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.

GPT-5 High

Proprietary

Closed source

Seed 1.8

Proprietary

Closed source

Release Timeline

When each model was launched

GPT-5 High was released on 2025-08-07, while Seed 1.8 was released on 2026-02-17.

Seed 1.8 is 6 months newer than GPT-5 High.

GPT-5 High

Aug 7, 2025

1.1 years ago

Seed 1.8

Feb 17, 2026

6 months ago

6mo newer

Knowledge Cutoff

When training data ends

GPT-5 High has a documented knowledge cutoff of 2024-09-30, while Seed 1.8's cutoff date is not specified.

We can confirm GPT-5 High's training data extends to 2024-09-30, but cannot make a direct comparison without Seed 1.8's cutoff date.

GPT-5 High

Sep 2024

Seed 1.8

Provider Availability

GPT-5 High is available from OpenAI. Seed 1.8 is available from DeepInfra.

GPT-5 High

openai logo
OpenAI
Input Price:Input: $1.25/1MOutput Price:Output: $10.00/1M

Seed 1.8

deepinfra logo
Deepinfra
Input Price:Input: $0.25/1MOutput Price:Output: $2.00/1M
* 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 GPT-5 High and Seed 1.8 side-by-side, then vote on the output you prefer.

GPT-5 High
✓ Preferred
Seed 1.8
Open in Playground

FAQ

Common questions about GPT-5 High vs Seed 1.8.

Which is better, GPT-5 High or Seed 1.8?

GPT-5 High and Seed 1.8 are closely matched on the LLM Stats Score at 34.1 and 34.2. GPT-5 High is made by OpenAI and Seed 1.8 is made by ByteDance. The best choice depends on your use case — compare their capability indexes, individual benchmarks, pricing, and limits above.

How does GPT-5 High compare to Seed 1.8 in benchmarks?

GPT-5 High scores AIME 2025: 94.6%, GPQA: 87.3%. Seed 1.8 scores CountBench: 96.3%, AIME 2025: 94.3%, VLMsAreBlind: 93.0%, MMLU: 92.3%, AI2D: 89.1%.

Is GPT-5 High cheaper than Seed 1.8?

Seed 1.8 is 5.0x cheaper for input tokens. GPT-5 High costs $1.25/M input and $10.00/M output via openai. Seed 1.8 costs $0.25/M input and $2.00/M output via deepinfra.

What are the context window sizes for GPT-5 High and Seed 1.8?

GPT-5 High supports 400K tokens and Seed 1.8 supports 256K tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

What are the main differences between GPT-5 High and Seed 1.8?

Key differences include LLM Stats Score (34.1 vs 34.2), context window (400K vs 256K), input pricing ($1.25 vs $0.25/M). See the full comparison above for benchmark-by-benchmark results.

Who makes GPT-5 High and Seed 1.8?

GPT-5 High is developed by OpenAI and Seed 1.8 is developed by ByteDance.