GPT-5 vs Grok 4: Flagship AI Model Comparison

Contents

• GPT-5 vs Grok 4: Overview
• Summary Comparison
• Model Specifications
• API Pricing
• Context Windows
• Benchmark Comparison
• Real-Time Data Access
• Ecosystem and Integration
• Use Case Recommendations
• FAQ
• Detailed Capability Comparison
• Real-Time Information Advantage Deep Dive
• Compliance and Scale Considerations
• Ecosystem Integration and Developer Experience
• Cost Analysis Beyond Token Pricing
• Risk Assessment
• Market Trends and Predictions
• Related Resources
• Sources

GPT-5 vs Grok 4: Overview

GPT-5 vs Grok 4: GPT-5.4 input $2.50, Grok 4 input $3.00. Both output at $15/M.

OpenAI: better ecosystem. Grok: real-time web access.

Pick OpenAI for general work. Pick Grok if developers need current data.

Summary Comparison

Data as of March 2026 from OpenAI docs, xAI docs, and benchmark publications.

Model Specifications

OpenAI GPT-5.4

Launched March 5, 2026. Standard context window: 272,000 tokens. Via API, extends to 1,050,000 tokens (anything above 272K billed at 2x the input rate). Input: $2.50/M, output: $15.00/M. Throughput: 45 tokens/second (published SLA).

Ships with native computer use capabilities. Screenshot understanding, mouse/keyboard automation, form filling, webpage navigation. Integration with Python code execution. Extended thinking enabled by default but can be toggled.

Available on ChatGPT Plus, Pro, Team, and API. Free tier (Go) has limited access. Pro tier ($200/month) gives unlimited reasoning compute.

xAI Grok 4

Launched early 2026. Context window: 256,000 tokens. Input: $3.00/M, output: $15.00/M. No extended context API tier published.

Scored 88% on GPQA Diamond (graduate-level science questions), beating GPT-5's 85%. Justifies the premium for science-heavy work.

Native access to X (Twitter) data. Real-time feeds, trending topics, sentiment analysis, breaking news: all without a separate browsing tool or tool-call overhead. Integrated search via X's database.

Code execution environment and web search available via tool calls. No computer use capabilities announced.

API Pricing

Head-to-Head Cost (as of March 2026)

OpenAI is marginally cheaper on standard pricing. The $0.50/M difference in input cost is negligible at scale. Both output prices are identical at $15.00/M.

Extended context flips the equation. GPT-5.4's extended context (>272K) bills at 2x input rate ($5.00/M). If the queries exceed 272K tokens frequently, Grok's 256K fixed cost may be more predictable. But Grok doesn't offer extended context via API, so the comparison is moot unless teams need mega-context.

Cost at Scale

A customer support system processing 1B tokens/month (500M in, 500M out):

• GPT-5.4 (standard context): (500M × $2.50 + 500M × $15.00) / 1M = $10,000/month
• Grok 4: (500M × $3.00 + 500M × $15.00) / 1M = $10,500/month

$500/month difference. Not material. Ecosystem and capability differences drive the decision.

Subscription Costs

For ChatGPT Plus ($20/month), users get access to GPT-5.4 with higher limits than free tier.

For xAI SuperGrok ($30/month), users get Grok 4 access.

$10/month premium for Grok's SuperGrok subscription.

Context Windows

Both fit standard documents, codebases, and research papers. Difference is negligible below 250K tokens.

For mega-context work (entire codebase analysis, 100+ document discovery), GPT-5.4 reaches 1.05M at the cost of 2x input surcharge above 272K. Grok maxes out at 256K.

If the workload involves frequent mega-context queries, GPT-5.4's extended context is an advantage despite the surcharge. Otherwise, the 16K difference is academic.

Benchmark Comparison

Mathematics (AIME 2025)

OpenAI GPT-5 scored 94-95% on AIME 2025 (competition-level math problems). xAI reported Grok 3 at 93.3%. Grok 4 scores not yet published on AIME 2025, but expected to exceed Grok 3.

Neither company has released head-to-head AIME benchmarks for GPT-5.4 vs Grok 4 on the same test conditions. The reported gap is 1-2 percentage points, which is within measurement noise given different evaluation methodologies.

Science (GPQA Diamond)

Grok 4: 88% on GPQA Diamond (graduate-level physics, chemistry, biology questions). GPT-5: 85% on the same benchmark.

This is Grok's clearest advantage. 3-point gap on expert-level questions is meaningful. For teams building domain-specific AI systems in science, Grok's higher accuracy justifies the premium.

Neither model should be trusted without review on PhD-level material. 88% still means ~1 in 8 answers is wrong.

Coding (SWE-bench Verified)

GPT-5.1 scored 76.3% on SWE-bench Verified (real GitHub issue resolution). Grok 4 hasn't published a comparable score. User reports suggest Grok and GPT are equivalent on practical coding tasks, with ecosystem advantage going to OpenAI (Canvas, code execution, GitHub Copilot integration).

General Knowledge (MMLU)

No recent published scores for GPT-5.4 or Grok 4 on MMLU. GPT-4 hit 86.4%. Expect both GPT-5.4 and Grok 4 to exceed 90%, but comparisons aren't published.

Real-Time Data Access

GPT-5.4 Approach

Browsing tool built in. Queries can trigger web searches. Searches are transparent in the chat interface. Latency adds 1-2 seconds per search. Occasionally fails (timeouts, blocked by robots.txt, JavaScript-heavy sites).

The browsing tool is reliable for text-heavy content (news, blogs, documentation). Less reliable for dynamic sites, paywall-protected content, and real-time data requiring complex navigation.

For questions about recent events, GPT-5.4 requires explicitly enabling web search, which adds latency and may fail.

Grok 4 Approach

Native X data access. Queries automatically check X's feeds, trending topics, and sentiment. No tool calls, no latency overhead, no failures. Current events, market sentiment, breaking news: all available natively.

Web search available via tool call, but not the primary interface. X data integration is the killer feature. Teams tracking social signals, market sentiment, or trending topics benefit from Grok's native integration.

Time zone matters. X's trending topics are global and refresh hourly. Grok surfaces current data without the latency of a browsing tool.

Ecosystem and Integration

OpenAI Advantages

Canvas is a dedicated editor for code and long-form writing. Real-time collaboration, syntax highlighting, markdown preview. No competing xAI feature.

Code execution runs inline. Python environment with package installation (numpy, pandas, matplotlib), persistent state. Teams prototyping data analysis or generating reports use Canvas + code execution heavily.

GitHub Copilot integration. GitHub Copilot Chat, IDE integration, CI/CD pipeline integration. If the dev team is already in the GitHub ecosystem, GPT-5.4 is native.

Compliance and large-scale features. SOC 2 Type II, HIPAA BAAs, FedRAMP authorization, EU data residency. Critical for regulated industries. Grok lags here.

ChatGPT ecosystem. Plugins, integrations, three years of third-party development. Mature plugin ecosystem for email, Slack, Notion, Zapier, etc.

xAI Grok Advantages

Real-time X data without tool-call latency. Trending topics, sentiment analysis, breaking news: all baked in.

Science reasoning edge. 88% GPQA Diamond vs 85% for GPT-5. Matters for research synthesis, patent analysis, technical due diligence.

No browsing tool failures. X data is guaranteed to return. GPT-5.4's browsing sometimes fails on dynamic content.

Community and open-source alignment. xAI is more transparent about training and model details. Some developers prefer this.

Use Case Recommendations

GPT-5.4 fits better for:

Dev teams in the OpenAI ecosystem. Canvas, code execution, GitHub Copilot integration, existing ChatGPT workflows. Switching costs are real. Stay put.

Regulated industries requiring compliance. Healthcare, finance, government. SOC 2, HIPAA, FedRAMP authorization are table stakes. Grok doesn't match OpenAI's certifications yet.

Extended-context work. 1.05M token context via API. Mega-context document analysis, legal discovery, patent searches. Grok maxes out at 256K.

Computer use and automation. Webpage navigation, screenshot understanding, form filling. xAI hasn't announced this.

Teams prioritizing ecosystem depth. ChatGPT plugins, years of integrations, Canvas, code execution, vision. OpenAI's ecosystem is unmatched.

Grok 4 fits better for:

Science and reasoning workloads. 88% GPQA Diamond. Graduate-level reasoning matters. Patent analysis, research synthesis, technical due diligence benefit from Grok's edge.

Real-time data and social signals. Native X integration. Trend tracking, market sentiment, breaking news. Grok's real-time data is native, not tool-call latency.

Cost-sensitive at extreme scale. $0.50/M difference in input cost. At 10B tokens/month, that's $5K/month savings. Grows with scale.

Teams skeptical of OpenAI. xAI's transparency and alignment focus appeal to some developers. Philosophical preference matters if both models are technically equivalent.

Long-document analysis under 256K tokens. Grok's 256K context is fixed cost, no surcharge. GPT-5.4's extended context (>272K) triggers 2x input cost. For documents landing just under the threshold, Grok's fixed cost is cheaper.

FAQ

Which is better overall?

OpenAI GPT-5.4 for ecosystem, compliance, and computer use. xAI Grok 4 for real-time data, science reasoning, and X integration. Neither dominates across all dimensions.

Which is cheaper?

OpenAI by $0.50/M on input tokens. Negligible at most scales. Subscription pricing (ChatGPT Plus $20 vs SuperGrok $30) favors OpenAI.

Which handles larger documents?

GPT-5.4 reaches 1.05M tokens via API (surcharge applies above 272K). Grok maxes at 256K. For mega-context, OpenAI wins.

Which is better at math?

OpenAI on AIME 2025 (94-95% vs Grok's 93.3%). Difference is small. Both are strong.

Which is better at science?

Grok 4 on GPQA Diamond (88% vs 85%). Clearer advantage here. For graduate-level reasoning, Grok edges ahead.

Can I use both?

Yes. Route real-time and X-data queries to Grok, compliance and computer-use work to GPT-5.4. Both expose REST APIs.

Which is better for real-time queries?

Grok, hands down. Native X data, no browsing tool failures, no latency. For news, trends, sentiment: Grok's the play.

Which should I choose?

If you're in OpenAI's ecosystem and don't need real-time X data: GPT-5.4. If you need bleeding-edge science reasoning and live market data: Grok 4. If budget is unlimited: use both, route tasks appropriately.

Detailed Capability Comparison

Mathematical Reasoning

GPT-5 leads slightly on AIME 2025 (94-95% vs 93.3%). But the gap is small. Different evaluation methodologies (pass@1 vs consensus@64, temperature settings, prompt format) can flip the ranking.

For production systems, neither model is reliable enough for expert-level math without verification. 1-5% error rates are too high for mission-critical calculations.

Graduate-Level Science

Grok 4 has a measurable advantage. 88% GPQA Diamond (graduate-level physics, chemistry, biology) vs GPT-5's 85%.

3-point gap on expert questions is meaningful. For teams building research synthesis systems, patent analysis tools, or technical due diligence platforms, Grok's edge justifies the premium.

But both models remain fallible. 88% means roughly 1 in 8 answers is wrong on PhD-level material. Human review is mandatory.

Coding Capability

GPT-5.1 scored 76.3% on SWE-bench Verified (solving real GitHub issues). Grok hasn't published a comparable score.

User reports suggest both are equivalent on practical coding tasks (refactoring, feature implementation, debugging). Neither dominates.

The advantage goes to OpenAI on ecosystem (Canvas, code execution) and GitHub Copilot integration, not raw capability.

Vision and Multimodal

GPT-5.4 has mature vision with multi-image reasoning. Analyze entire design mockups, interpret diagrams, OCR documents, compare versions side-by-side.

Grok 2 Vision exists but is less documented. Quality unknown.

For applications centered on vision (design review, document analysis, visual Q&A), GPT-5.4 is safer.

Real-Time Information Advantage Deep Dive

X Data Integration Mechanics

Grok has native access to X's real-time feeds. The queries automatically check trending topics, recent posts, sentiment analysis.

No tool-call overhead. No latency. No failures. Pure API call, same as regular inference.

Examples where this matters:

• Market sentiment analysis (crypto trends, stock reactions)
• Breaking news tracking
• Trending topic analysis
• Social movement tracking

All available instantly within Grok without leaving the interface.

GPT-5.4 Browsing Tool

OpenAI's browsing tool is a separate capability. Queries can trigger web searches, but:

• Add 1-2 seconds latency per search
• May fail on dynamic sites, JavaScript-heavy pages, paywalled content
• Robots.txt rules sometimes block queries
• Not native to the model, requires tool-call negotiation

For recent events, GPT-5.4 requires explicit search enabling. Grok returns current data transparently.

Comparison on Timeliness

Query: "What's trending on X right now?"

Grok: Instant. Returns current top 10 trending topics with context.

GPT-5.4: Requires web search. May take 3-5 seconds. Sometimes fails to return results.

Query: "How did the market react to the latest Fed announcement?"

Grok: Checks X feeds immediately. Returns sentiment, top posts, context.

GPT-5.4: Requires web search. Returns news articles, analysis. More comprehensive but slower.

Practical Impact

For applications where real-time matters (financial dashboards, news aggregation, social analytics), Grok's native X integration is a genuine product advantage, not just a marketing claim.

Compliance and Scale Considerations

OpenAI's Compliance Moat

GPT-5.4 has:

• SOC 2 Type II certification
• HIPAA BAA available
• FedRAMP authorization (for government)
• EU data residency options
• Dedicated support with account managers

These aren't theoretical. Healthcare systems, financial institutions, and government agencies require these certifications to deploy. OpenAI has them. Grok doesn't yet.

Grok's Path to Compliance

xAI is smaller. Compliance certifications take time and resources. Grok likely achieves SOC 2 within 12 months and HIPAA BAA within 24 months.

Teams in regulated industries should check back Q3 2026 before deciding Grok is off-limits.

Budget Impact of Compliance

Certified models sometimes carry a premium (OpenAI's pricing for certified instances can be 10-30% higher). As Grok gets certified, pricing may increase.

Data Residency and Privacy

Both OpenAI and xAI are US companies. Data residency options (EU servers, private deployment) differ. Review requirements before committing.

Ecosystem Integration and Developer Experience

OpenAI's Ecosystem Depth

ChatGPT plugins ecosystem. GitHub Copilot Chat. OpenAI API integrations (Zapier, Make, n8n).

Canvas real-time collaboration. Code execution with persistent state.

Computer use (automated form filling, webpage navigation, screenshot understanding).

Years of third-party development mean mature integrations. IDEs have built-in support. CI/CD pipelines have pre-built steps for OpenAI models.

Switching from GPT-5.4 to anything else means losing all this integration work.

Grok's Ecosystem

Younger platform. Integrations are emerging but not mature. No equivalent to Canvas or code execution yet.

The advantage: Clean slate. Not encumbered by legacy decisions. Potential to be architecturally superior.

Integration Time Estimate

Moving a production GPT-5.4 system to Grok 4:

• API calls: 10 minutes (model parameter change)
• Prompt tuning: 1-2 hours (different models respond to prompts differently)
• Feature porting: 1-5 days (Canvas, code execution don't have Grok equivalents)
• Testing and QA: 2-5 days
• Compliance review: Variable (if regulated)

Realistic estimate: 1-2 weeks for a mature product.

Cost Analysis Beyond Token Pricing

Hidden Costs

OpenAI:

• Compliance audits (if required)
• ChatGPT Plus/Pro subscriptions for teams ($20-200/month per user)
• Dedicated support contracts (if needed)

Grok:

• Smaller provider, less mature integrations (may require custom development)
• Fewer pre-built plugins and tools
• Learning curve on xAI documentation and ecosystem

Break-Even Analysis

If Grok is cheaper on tokens by $500/month but requires $10K/year custom development to match OpenAI's integrations, GPT-5.4 is cheaper overall.

Quantify integration costs:

• Developer time to port features: X hours × salary rate
• Maintenance burden: Y hours/month × salary rate × 12 months
• Tool licensing (Canvas equivalent?): Z$/month

Add that to token costs for total cost of ownership.

Risk Assessment

OpenAI Risk Factors

• Market concentration: One company dominates. API changes affect all customers.
• Pricing increases: As OpenAI matures, prices may increase.
• Model deprecation: Older models eventually stop working. Migration required.

Grok Risk Factors

• Company stability: xAI is younger. Exit risk, acquisition risk.
• Platform maturity: Fewer battle-tested integrations. Outages are more likely.
• Feature completeness: Missing vision, extended reasoning, computer use.

Risk Mitigation

Use both. Multi-vendor strategy reduces risk. If one provider fails or increases prices, migrate to the other.

Cost: 2x token expense during evaluation period. Worth it for mission-critical work.

Market Trends and Predictions

GPT-5.4 Trajectory

Expect incremental improvements. GPT-5.5 will ship in Q4 2026 with ~5% capability gains and same pricing. OpenAI is committed to quarterly releases.

Pricing may decrease as competition increases. Or increase as demand grows. Unpredictable.

Grok 4 Trajectory

xAI is in growth mode. Expect rapid iteration. Grok 5 in Q3 2026. Vision improvements. Extended reasoning announcement likely.

Compliance certifications coming. Product maturation accelerating.

Price stability: Expect pricing to remain competitive as xAI scales up.

Broader LLM Market

Budget models (Nano, Flash) will commoditize. Flagship models (GPT-5, Grok 4) will differentiate on reasoning and capabilities, not cost.

Specialized models (reasoning, vision, code) will emerge and fragment the market.

Related Resources

• LLM Pricing Comparison
• OpenAI GPT Models and Pricing
• xAI Grok Models and Pricing
• ChatGPT 5 vs Grok 4 Deep Dive
• GPT-5 Codex vs Standard GPT-5

Sources

• OpenAI GPT-5.4 Announcement
• OpenAI API Pricing
• xAI Grok 4 Models and Pricing
• xAI Documentation
• ChatGPT Plans and Pricing
• SuperGrok Plans
• DeployBase LLM Pricing Tracker (as of March 21, 2026)