GPT-5.3-Codex vs DeepSeek V4.1 Flash
Detailed technical comparison between GPT-5.3-Codex (OpenAI) and DeepSeek V4.1 Flash (DeepSeek). Review live API token pricing, context window capabilities, time-to-first-token latency, and verified benchmark scores side-by-side.
Comparison Snapshot
DeepSeek V4.1 Flash
1,048,576 tokensTie
Equal CapabilityTie
Equal SpeedDeepSeek V4.1 Flash
$0.15 / MTokGPT-5.3-Codex
GPT-5.3-Codex is an advanced artificial intelligence model engineered by OpenAI. Tailored for complex multi-step reasoning, programming synthesis, and extended document comprehension, GPT-5.3-Codex represents a key architectural iteration in the OpenAI model family. First released in 2026-02-24, it serves enterprise developers, research teams, and autonomous system architects requiring strict instruction compliance. Featuring an input capacity of 400,000 tokens (approximately 533 words), GPT-5.3-Codex processes multi-file code repositories, lengthy technical reports, and complex prompts in a single inference call.
DeepSeek V4.1 Flash
DeepSeek V4.1 Flash is an advanced artificial intelligence model engineered by DeepSeek. Tailored for complex multi-step reasoning, programming synthesis, and extended document comprehension, DeepSeek V4.1 Flash represents a key architectural iteration in the DeepSeek model family. First released in 2026-09-10, it serves enterprise developers, research teams, and autonomous system architects requiring strict instruction compliance. Featuring an input capacity of 1,048,576 tokens (approximately 1,398 words), DeepSeek V4.1 Flash processes multi-file code repositories, lengthy technical reports, and complex prompts in a single inference call.
Technical Specifications
🏆 = Superior Spec| Specification | GPT-5.3-Codex | DeepSeek V4.1 Flash |
|---|---|---|
| Provider | OpenAI | DeepSeek |
| Context Window | 400,000 tokens | 1,048,576 tokens🏆 |
| Agent Suitability | Not yet benchmarked | Not yet benchmarked |
| Time to First Token (TTFT) | No public TTFT data | No public TTFT data |
| Deployment Model | managed api | self hostable |
| Production Stability | Stable GA (est.) | Beta Access (est.) |
| API Available | Yes | Yes |
| Released Date | 2026-02-24 | 2026-09-10 |
API Pricing Comparison
Input Price per Million Tokens
GPT-5.3-Codex
$1.75
DeepSeek V4.1 Flash
$0.15
Output Price per Million Tokens
GPT-5.3-Codex
$14.00
DeepSeek V4.1 Flash
$0.60
💡 Cost Ratio: DeepSeek V4.1 Flash is 11.7x cheaper per input token than GPT-5.3-Codex.
Want to test both models live?
Run side-by-side prompt benchmarks in our dynamic multi-model Sandbox. Compare execution speeds, latency metrics, and compute actual costs in real-time.
Benchmark Performance Metrics
Standardized Scores (0–100%)Scores show verified raw accuracy percentages across standardized AI evaluation suites. Higher bars indicate superior performance in that domain.
GPT-5.3-Codex Quirks & Gotchas
No developer gotchas reported.
DeepSeek V4.1 Flash Quirks & Gotchas
No developer gotchas reported.
Explore Other Popular Comparisons
GPT-5.3-Codex vs Fugu Max
Compare context windows, live API token prices, and benchmark scores.
SIDE-BY-SIDE REVIEWGPT-5.3-Codex vs Fugu Ultra v2
Compare context windows, live API token prices, and benchmark scores.
SIDE-BY-SIDE REVIEWGPT-5.3-Codex vs Ling 3.0 Flash VL
Compare context windows, live API token prices, and benchmark scores.
SIDE-BY-SIDE REVIEWGPT-5.3-Codex vs Mercury 2.5
Compare context windows, live API token prices, and benchmark scores.
SIDE-BY-SIDE REVIEWGPT-5.3-Codex vs GPT-6 Astra
Compare context windows, live API token prices, and benchmark scores.
SIDE-BY-SIDE REVIEWGPT-5.3-Codex vs GPT-6 Astra Pro
Compare context windows, live API token prices, and benchmark scores.