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Open weightsByteDance Seed/10 trustVerified
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Seed-OSS-36B

Apache-2.0 open 36B model with 512K context for reasoning and agents.

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About

ByteDance's Seed team released Seed-OSS-36B as its first open model family: 36B parameters across base, base-without-synthetic-data, and instruct variants, all under Apache 2.0 with no licensing fees for commercial use. The standout spec is a native 512K-token context window, aimed at long documents and extended reasoning chains, and the team says it trains well on only 12T tokens.

It is explicitly positioned for international (non-China) use cases. As with most vendor-reported results, treat the benchmark claims as directional until independent evals land.

Specs

Context window

512K

Pricing

Free quota

API access

Weights

Open weights

Released

August 20, 2025

Benchmarks

  • Native 512K-token context window
  • Trained on 12T tokens; strong results on open benchmarks (ByteDance-reported)

Provider-reported unless a source says otherwise. Benchmarks are marketing-adjacent by nature — treat them as directional.

Use cases

codeagentsresearch

Trust score — 8/10

/10 trustVerified

Scored 8/10 (verified tier, metrics-v1). Evidence: ByteDance Seed team official repo + HF org, Apache-2.0 with no commercial restriction; 512K context and 12T-token training figure from official model card; Benchmark claims are vendor-reported; independent evals not yet confirmed. License: Apache-2.0 confirmed from official GitHub repo and HF model card..

How the trust score is built

Full methodology →
Adoption · stars/downloads, log-scaled vs peers
8.0/10
Maintenance · recency, releases, issue load
8.0/10
Openness · license + docs
9.0/10
Manual review · sanity read + red-flag check
8.0/10
  • · ByteDance Seed team official repo + HF org, Apache-2.0 with no commercial restriction
  • · 512K context and 12T-token training figure from official model card
  • · Benchmark claims are vendor-reported; independent evals not yet confirmed

More in the seed-oss family

Sources