Claude Sonnet 4 vs Seed 1.8
Seed 1.8 leads the LLM Stats Score 34.2 to 24.3. Seed 1.8 is 8.7x cheaper per token.
Anthropic · ByteDance · Updated for 2026
Which is better?
Seed 1.8 leads the overall LLM Stats Score 34.2 to 24.3, ranking #91 overall.
In the 3 individual benchmarks reported for both models, Seed 1.8 wins 3; this is a narrower head-to-head signal than the composite indexes.
On price, Seed 1.8 is roughly 8.7x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.
Seed 1.8 also accepts a larger context window (256,000 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 Sonnet 4
- you want predictable pricing at $3.00/M input and $15.00/M output
Choose Seed 1.8
- overall performance matters — it scores 34.2 and ranks #91 on LLM Stats
- your work emphasizes reasoning — it leads those capability indexes
- you value its reported benchmark strengths — it wins 3 of 3 exact shared results
- cost matters — it's about 8.7x cheaper per token
- you process long inputs — it offers a 256,000 token context window
- you want the most recent training data — it shipped Feb 2026
At a glance
The differences that matter most.
Capability indexes
Additional strengths measured across groups of related public benchmarks
Individual benchmarks
8 reported for Claude Sonnet 4 · 57 for Seed 1.8
Claude Sonnet 4 outperforms in 0 benchmarks, while Seed 1.8 is better at 3 benchmarks (AIME 2025, MMMU, SWE-Bench Verified).
Seed 1.8 significantly outperforms across most benchmarks.
Human preference
Blind head-to-head votes and playground preference scores
Pricing Analysis
Price comparison per million tokens
For input processing, Claude Sonnet 4 ($3.00/1M tokens) is 12.0x more expensive than Seed 1.8 ($0.25/1M tokens).
For output processing, Claude Sonnet 4 ($15.00/1M tokens) is 7.5x more expensive than Seed 1.8 ($2.00/1M tokens).
In conclusion, Claude Sonnet 4 is more expensive than Seed 1.8.*
* Using a 3:1 ratio of input to output tokens
Context Window
Maximum input and output token capacity
Seed 1.8 accepts 256,000 input tokens compared to Claude Sonnet 4's 200,000 tokens. Seed 1.8 can generate longer responses up to 256,000 tokens, while Claude Sonnet 4 is limited to 64,000 tokens.
Input capabilities
Documented input modalities across available providers
Both Claude Sonnet 4 and Seed 1.8 support multimodal inputs.
They are both capable of processing various types of data, offering versatility in application.
Claude Sonnet 4
Seed 1.8
License
Usage and distribution terms
Both models are licensed under proprietary licenses.
Both models have usage restrictions defined by their respective organizations.
Proprietary
Closed source
Proprietary
Closed source
Release Timeline
When each model was launched
Claude Sonnet 4 was released on 2025-05-22, while Seed 1.8 was released on 2026-02-17.
Seed 1.8 is 9 months newer than Claude Sonnet 4.
May 22, 2025
1.3 years ago
Feb 17, 2026
6 months ago
9mo newerKnowledge Cutoff
When training data ends
Neither model specifies a knowledge cutoff date.
Unable to compare the recency of their training data.
Provider Availability
Claude Sonnet 4 is available from Anthropic, Bedrock, Google. Seed 1.8 is available from DeepInfra.
Claude Sonnet 4
Seed 1.8
Outputs Comparison
Judge for yourself.
Run your own prompts against Claude Sonnet 4 and Seed 1.8 side-by-side, then vote on the output you prefer.
FAQ
Common questions about Claude Sonnet 4 vs Seed 1.8.