Key Takeaways
Seed OSS 36B Instruct wins:
- Cheaper input tokens
- Cheaper output tokens
- Better at math
GPT-5.3 Codex wins:
- Larger context window
- Faster response time
- Higher intelligence benchmark
- Better at coding
- Supports vision
Price Advantage
Seed OSS 36B Instruct
Benchmark Advantage
GPT-5.3 Codex
Context Window
GPT-5.3 Codex
Speed
GPT-5.3 Codex
Pricing Comparison
Price Comparison
| Metric | Seed OSS 36B Instruct | GPT-5.3 Codex | Winner |
|---|---|---|---|
| Input (per 1M tokens) | $0.90 | $1.75 | Seed OSS 36B Instruct |
| Output (per 1M tokens) | $0.90 | $14.00 | Seed OSS 36B Instruct |
| Cache Read (per 1M) | $0.45 | $0.17 | GPT-5.3 Codex |
Using a 3:1 input/output ratio, Seed OSS 36B Instruct is 81% cheaper overall.
Seed OSS 36B Instruct Providers
No provider data available
GPT-5.3 Codex Providers
No provider data available
Benchmark Comparison
6
Benchmarks Compared
0
Seed OSS 36B Instruct Wins
3
GPT-5.3 Codex Wins
Benchmark Scores
| Benchmark | Seed OSS 36B Instruct | GPT-5.3 Codex | Winner |
|---|---|---|---|
Intelligence Index Overall intelligence score | 25.2 | 54.0 | |
Coding Index Code generation & understanding | 16.7 | 53.1 | |
Math Index Mathematical reasoning | 84.7 | - | - |
MMLU Pro Academic knowledge | 81.5 | - | - |
GPQA Graduate-level science | 72.6 | 91.5 | |
LiveCodeBench Competitive programming | 76.5 | - | - |
GPT-5.3 Codex significantly outperforms in coding benchmarks.
Cost vs Quality
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Seed OSS 36B Instruct
Other models
Context & Performance
Context Window
Seed OSS 36B Instruct
N/A
tokens
GPT-5.3 Codex
400,000
tokens
Speed Performance
| Metric | Seed OSS 36B Instruct | GPT-5.3 Codex | Winner |
|---|---|---|---|
| Tokens/second | 29.9 tok/s | 68.3 tok/s | |
| Time to First Token | 1.58s | 81.66s |
GPT-5.3 Codex responds 128% faster on average.
Capabilities
Feature Comparison
| Feature | Seed OSS 36B Instruct | GPT-5.3 Codex |
|---|---|---|
| Vision (Image Input) | ||
| Tool/Function Calls | ||
| Reasoning Mode | ||
| Audio Input | ||
| Audio Output | ||
| PDF Input | ||
| Prompt Caching | ||
| Web Search |
License & Release
| Property | Seed OSS 36B Instruct | GPT-5.3 Codex |
|---|---|---|
| License | Proprietary | Proprietary |
| Author | Bytedance-seed | OpenAI |
| Released | Unknown | Feb 2026 |
Seed OSS 36B Instruct Modalities
Input
Output
GPT-5.3 Codex Modalities
Input
textimage
Output
text