Seed 1.8 (Reasoning)

by ByteDance

Seed 1.8 (Reasoning) is a reasoning model from ByteDance, released on February 17, 2026. It has a 256K-token context window and can generate up to 256K output tokens. API pricing is $0.25 per 1M input tokens and $2 per 1M output tokens. It ranks #67 of 220 models by Intelligence Score with a score of 34.

Optimized specifically for multimodal agent scenarios. It features enhanced agent capabilities, upgraded multimodal comprehension, and more flexible context management.

Key specs

ProviderByteDance
Release date2026-02-17
Licenseproprietary
Context window256K tokens
Max output256K tokens
Input price$0.25 / 1M tokens
Output price$2 / 1M tokens
Intelligence Score34
Coding index19.4

Quick answers

What is the context window of Seed 1.8 (Reasoning)?

Seed 1.8 (Reasoning) has a context window of 256K tokens, with a maximum output of 256K tokens per response.

How much does Seed 1.8 (Reasoning) cost?

Seed 1.8 (Reasoning) costs $0.25 per 1M input tokens and $2 per 1M output tokens through the API.

Is Seed 1.8 (Reasoning) open source?

No. Seed 1.8 (Reasoning) is a proprietary model from ByteDance (proprietary license).

When was Seed 1.8 (Reasoning) released?

ByteDance released Seed 1.8 (Reasoning) on February 17, 2026.

How does Seed 1.8 (Reasoning) compare to Claude Opus 5.5 (Reasoning)?

Seed 1.8 (Reasoning) scores 34 on the Intelligence Score versus 60.5 for Claude Opus 5.5 (Reasoning), the current #1. Input pricing is $0.25 vs $4 per 1M tokens.

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