GPT-5.3-Codex vs Seed 1.6 Flash
How do these models stack up? Below is an expert side-by-side comparison of specifications, context window capacity, live pricing per million tokens, and standardized benchmark scores for GPT-5.3-Codex and Seed 1.6 Flash.
GPT-5.3-Codex
GPT-5.3-Codex is OpenAI’s most advanced agentic coding model, combining the frontier software engineering performance of GPT-5.2-Codex with the broader reasoning and professional knowledge capabilities of GPT-5.2. It achieves state-of-the-art results...
Seed 1.6 Flash
Seed 1.6 Flash is an ultra-fast multimodal deep thinking model by ByteDance Seed, supporting both text and visual understanding. It features a 256k context window and can generate outputs of...
Technical Specifications
| Specification | GPT-5.3-Codex | Seed 1.6 Flash |
|---|---|---|
| Provider | OpenAI | ByteDance |
| Context Window | 400,000 tokens | 262,144 tokens |
| Agent Suitability | N/A | N/A |
| Time to First Token (TTFT) | N/A | N/A |
| Deployment Model | managed api | managed api |
| Production Stability | stable | stable |
| API Available | Yes | Yes |
| Released Date | 2026-02-24 | 2025-12-23 |
API Pricing Comparison
Input Price per Million Tokens
GPT-5.3-Codex
$1.75
Seed 1.6 Flash
$0.07
Output Price per Million Tokens
GPT-5.3-Codex
$14.00
Seed 1.6 Flash
$0.30
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Benchmark Performance Metrics
Scores show the raw performance percentages verified across key evaluation suites. Higher bars indicate superior accuracy and capability in that domain.
GPT-5.3-Codex Quirks & Gotchas
No developer gotchas reported.
Seed 1.6 Flash Quirks & Gotchas
No developer gotchas reported.