GPT-5.3 Chat vs Grok 4.3
Benchmarks, API Token Pricing, Context Window & Speed Comparison
Related topics (12)
GPT-5.3 Chat by OpenAI and Grok 4.3 by xAI represent two of the frontier AI models analyzed in our comprehensive 2026 AI benchmark and LLM comparison. In this head-to-head evaluation, we examine API token pricing, context window specifications, inference speed (tokens per second), and empirical reasoning performance. From a pure economic perspective, GPT-5.3 Chat holds a notable pricing advantage for token ingestion. On output generation, GPT-5.3 Chat is more economical per million generated tokens. In data-heavy architectures requiring extensive repository or document analysis, Grok 4.3 provides an expanded memory horizon with 1,000K tokens. In latency-sensitive production environments, GPT-5.3 Chat leads in tokens-per-second throughput, making it ideal for real-time conversational agents and high-concurrency workflows. Below is the complete empirical head-to-head breakdown across cost, speed, context, and capability matrices.
Changez et Comparez les Modèles
Select any AI models from our verified benchmark database to generate live side-by-side matrices.
GPT-5.3 Chat
Conversationnel 5.3un chat-tuned GPT-5.3 covering conversation, writing et outil flux de travail.
$0.00 / 1M
$0.00 / 1M
128K tokens
77%
Grok 4.3
Grok par défautde xAI standard équilibré général-purpose modèle combining 1M contexte, robust agentic outil support, et inférieur hallucination rates.
$1.25 / 1M
$2.50 / 1M
1M tokens
71.4%
Différences Clés en un Coup d’Œil
- GPT-5.3 Chat is 1.0x cheaper for API usage (input + output tokens combined).
- Grok 4.3 has a larger context window (1M vs 128K tokens).
- GPT-5.3 Chat is faster at 138 tok/s vs 110 tok/s.
- GPT-5.3 Chat leads on SWE-bench coding (77.0% vs 71.4%).
| Caractéristique | GPT-5.3 Chat | Grok 4.3 |
|---|---|---|
Intelligence Index Composite reasoning & knowledge score (0-100) | 69 | 71 |
Provider | OpenAI | xAI |
Input Price Cost per million input tokens | $0.00 / 1M | $1.25 / 1M |
Output Price Cost per million output tokens | $0.00 / 1M | $2.50 / 1M |
Blended Price Weighted 7:2:1 cache:input:output per 1M | $0.00 / 1M | $0.72 / 1M |
Context Window Maximum input + output tokens | 128K tokens~192 A4 pages of text | 1M tokens~1,500 A4 pages of text |
Max Output Tokens Per single request | 16K | 66K |
Throughput Speed Tokens generated per second | 138 tok/s | 110 tok/s |
SWE-bench Verified Real-world software engineering | 77% | 71.4% |
GPQA Diamond Graduate-level reasoning | 78% | 73.5% |
Cached Input Price Prompt caching discount per 1M tokens | $0.00 / 1M | $0.31 / 1M |
Qui gagne où ?
At-a-glance decision frameworkScores de Benchmarks Vérifiés
Official evaluation metrics verified by independent third-party research labs.
Industry benchmark evaluating real-world GitHub issue resolution and multi-file debugging.
Challenging questions created by domain experts to test complex PhD-level reasoning.
Hardened reasoning and academic knowledge benchmark with reduced lucky-guess probability.
Crowdsourced human preference evaluation based on blind, head-to-head model battles.
Extremely difficult, closed-ended questions spanning the frontier of human expert knowledge.
Autonomous multi-step tasks executed inside a real command-line terminal environment.
Research-grade coding problems drawn from real scientific and numerical workloads.
Contamination-free competitive programming problems collected continuously over time.
American Invitational Mathematics Examination — multi-step Olympiad-level reasoning.
Accuracy when reasoning over very large inputs that fill the model context window.
Tokens emitted per second during active generation streaming.
Latence et Temps de Réponse
Time to first token (TTFT) and estimated end-to-end response time for a typical 500-token response.
Simulateur Interactif de Coût de Tokens
Adjust sliders to calculate projected monthly cloud API spending with prompt caching discounts.
GPT-5.3 Chat · Strengths & Key Advantages
- Refined conversationnel ton et instruction following
- bon à au format long writing et editing
- très bon à structuré au format long writing
Considerations & Trade-offs
- Subscription-seulement, no public API tarification
- fenêtre de contexte well below le développeur palier
Grok 4.3 · Strengths & Key Advantages
- Dependable balance de multi-étapes raisonnement, codage, et multimodal conversation
- massif 1M-token fenêtre de contexte avec significantly suppressed hallucination rates
- Consistent function calling et JSON sortie fidelity à travers complexe schemas
Considerations & Trade-offs
- Trails moyen-2026 de pointe leaders sur PhD-level STEM competitions
- sortie tarification de $15/1M est supérieur que subsequent Grok 4.5 et 4.7 releases
Token Use & Task Economics
Estimated cost and token consumption to complete one representative agentic task.
| Metric | GPT-5.3 Chat | Grok 4.3 |
|---|---|---|
Cost per Task Estimated USD to finish one task | $2.20 | $1.35 |
Output Tokens / Task Tokens generated per task | 56K | 46K |
Reasoning Tokens / Task Thinking tokens burned per task | 31K | 22K |
Spécifications Techniques
Architecture, release timeline, capabilities, and modalities.
| Caractéristique | GPT-5.3 Chat | Grok 4.3 |
|---|---|---|
| Official API Model ID (SDK) | gpt-5-3-chat | grok-4-3-latest |
| API Protocol | OpenAI Responses API & Chat Completions v1 | xAI REST API (OpenAI-Compatible) |
| Release Date | 2026-03 | 2026-04 |
| Knowledge Cutoff | November 2025 | January 2026 |
| Architecture | Chat-tuned unified reasoning model | Colossus-Scale Mixture-of-Experts |
| Parameters | Confidential | Confidential |
| Enterprise Rate Limits (RPM / TPM) | 10,000 – 30,000 RPM (Tier 5 Enterprise) · 800,000 – 2,000,000 TPM | 5,000 – 15,000 RPM (Production Tier) · 4,000,000 – 10,000,000 TPM |
| Long-Context Tier (>128K/200K) | Free across full context window (only KV-cache VRAM scales) | Flat rate ($1.25/1M in) across full 1000K window |
| Prompt Cache Policy & TTL | Automatic prefix KV-caching in vLLM / SGLang (0 cost) | Cached input at $0.31/1M tokens |
| Computer Use / GUI Agent | Supported (Screen coordinate grounding, browser & desktop GUI action loops) | API / CLI Tool-Use & DOM Agent ready (no raw pixel desktop click loop) |
| MCP & Parallel Tool Calling | Native MCP Client/Server ready · Parallel function calling | Native MCP Client/Server ready · Parallel function calling · 100% Strict JSON Schema |
| Web Search Grounding & Sandbox | Native Web Search tool + Hosted Code Interpreter & File Search RAG | Real-time Web & X (Twitter) Search Grounding + Code Execution |
| Official Fine-Tuning Support | Supervised Fine-Tuning (SFT), Direct Preference (DPO) & Reinforcement Fine-Tuning (RFT) | API Prompt Engineering & RAG Distillation |
| Multimodal Token Billing | Text BPE (~4 chars/token) · Vision (~258–765 tokens per image tile) | Text BPE (~4 chars/token) · Vision (~258–765 tokens per image tile) |
| Quantization & Min GPU VRAM | Cloud-Hosted Proprietary (FP8 / BF16 Tensor Core Cluster) · Zero Local VRAM Required (100% Serverless Cloud API) | Cloud-Hosted Proprietary (FP8 / BF16 Tensor Core Cluster) · Zero Local VRAM Required (100% Serverless Cloud API) |
| Safety & Frontier Classification | OpenAI Preparedness Framework Audited & System Card Published | xAI Production Safety & Alignment Verified |
| Enterprise Compliance (ZDR/HIPAA/SOC2) | SOC2 Type II · GDPR · Zero Data Retention (ZDR) & HIPAA BAA Available on Enterprise Tier | SOC2 Type II · GDPR · Zero Data Retention (ZDR) & HIPAA BAA Available on Enterprise Tier |
| Input Modalities | text, vision | text, vision |
| Output Modalities | text | text |
GPT-5.3 Chat vs Grok 4.3: Réponses Rapides (FAQ)
Which is more intelligent, GPT-5.3 Chat or Grok 4.3?
Grok 4.3 is more intelligent. It scores 71 compared with 69 on the composite Intelligence Index.
Which model is faster?
GPT-5.3 Chat is faster, generating 138 tokens per second compared with 110 tokens per second.
Which model is cheaper to run?
GPT-5.3 Chat is cheaper at $0.00 per 1M tokens blended, compared with $0.72 (7:2:1 cache:input:output ratio).
Which model has lower latency?
Grok 4.3 has lower latency, with a time to first token of 0.65s compared with 1.06s.
Which model has a larger context window?
Grok 4.3 has a larger context window, supporting 1M tokens compared with 128K tokens.
Verdict
Verdict & Model Selection Recommendation: Choose GPT-5.3 Chat if your priority is Conversational and writing work in ChatGPT. Its performance in demanding tasks justifies its operational token cost. Choose Grok 4.3 if your workflow prioritizes Enterprise knowledge retrieval, daily developer assistance, and general-purpose reasoning. For large-scale batch processing or customer-facing conversational interfaces, its balance of speed and economics delivers superior ROI.
Questions fréquentes
How does GPT-5.3 Chat compare to Grok 4.3 in API token pricing and cost per token?+
GPT-5.3 Chat costs $0.00 per 1M input tokens and $0.00 per 1M output tokens, whereas Grok 4.3 costs $1.25 input and $2.50 output. Overall, GPT-5.3 Chat is the more cost-effective model for high-volume API pipelines. Both models support prompt caching discounts of up to 90% for repeated prompt prefixes.
Which model has a larger context window: GPT-5.3 Chat or Grok 4.3?+
GPT-5.3 Chat supports a context window of 128K tokens (~96k words), while Grok 4.3 supports 1,000K tokens (~750k words). Therefore, Grok 4.3 can process more textual data and document context in a single prompt.
Which AI model is better for software engineering and coding: GPT-5.3 Chat or Grok 4.3?+
GPT-5.3 Chat scores 77% on SWE-bench Verified while Grok 4.3 scores 71.4%. For autonomous software engineering and multi-file debugging, GPT-5.3 Chat holds the verified benchmark lead.
What is the difference in reasoning capability and extended thinking between GPT-5.3 Chat and Grok 4.3?+
GPT-5.3 Chat features native chain-of-thought extended thinking mode with configurable reasoning effort. In contrast, Grok 4.3 provides chain-of-thought reasoning depth for complex math and science.
How does inference speed (tokens per second) compare between GPT-5.3 Chat and Grok 4.3?+
GPT-5.3 Chat generates approximately 138 tokens per second, while Grok 4.3 delivers 110 tokens per second. In latency-sensitive production environments, GPT-5.3 Chat provides faster time-to-first-token (TTFT) and higher streaming response velocity.
Can you implement a tiered LLM routing setup combining GPT-5.3 Chat and Grok 4.3 to optimize costs?+
Yes! High-efficiency architectures route high-frequency routine classification and conversational tasks to GPT-5.3 Chat to save operational costs, and dynamically escalate complex architectural queries or reasoning tasks to Grok 4.3. This tiered routing pattern cuts overall API bills by up to 70%.
Understand key metrics like context window, token pricing, reasoning mode, and SWE-bench scores in our comprehensive AI glossary.
Related reading
- GPT-5.3 Chat vs GPT-5.2 Pro: Benchmarks, Pricing & Speed ComparisonComparer
- GPT-5.4 nano vs GPT-5.3 Chat: Benchmarks, Pricing & Speed ComparisonComparer
- Grok 4.3 vs Grok Build 0.1: Benchmarks, Pricing & Speed ComparisonComparer
- Grok 4.5 vs Grok 4.3: Benchmarks, Pricing & Speed ComparisonComparer
- Aion-3.0 vs Aion-Mini: Benchmarks, Pricing & Speed ComparisonComparer
- Aion-3.0 vs Gemini 3.6 Flash: Benchmarks, Pricing & Speed ComparisonComparer
Les scores de benchmarks, tarifs par token et limites évoluent rapidement. Vérifiez toujours les spécifications actuelles sur la documentation officielle du fournisseur.
Sources: GetInfoUs Independent AI Benchmarks & Official API Specs