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ChatGPT 5 vs Grok 4: AI Chatbot Comparison

Deploybase · February 2, 2026 · Model Comparison

Contents

ChatGPT 5 vs Grok 4 Overview

ChatGPT 5 vs Grok 4 is the focus of this guide. Both frontier-tier models, both expensive, both worth it for different things. ChatGPT 5 lands March 2026 with 1M context on API, 272K on-device. Ecosystem player:code, content, depth. Grok 4 is reasoning-first, real-time data, science problems, 256K context.

Same price tier. Different priorities. Pick based on what developers actually need.

Summary Comparison

DimensionChatGPT 5Grok 4Grok 4.1 FastEdge
API input price$1.25/M$3.00/M$0.20/MGrok 4.1
API output price$10.00/M$15.00/M$0.50/MGrok 4.1
Max context (API)1,050,000256,0002,000,000Grok 4.1
Context (on-device)272,000256,000N/AChatGPT
Subscription cost$20/mo (Plus)$30/mo (SuperGrok)Free tier availableChatGPT
GPQA Diamond score~85%88%92%Grok 4.1
Code (SWE-bench)76.3%73%80%ChatGPT
Real-time dataBrowsing toolNative X feedNative X feedGrok
Video generationSora 2AuroraAuroraChatGPT
Ecosystem integrationCanvas, code execDeepSearchX integrationChatGPT

Data from OpenAI API, xAI docs, and DeployBase API, March 21, 2026.

API Pricing

Per-Million-Token Costs

ChatGPT 5:

  • Input: $1.25 per million tokens
  • Output: $10.00 per million tokens

Grok 4:

  • Input: $3.00 per million tokens
  • Output: $15.00 per million tokens

Grok 4.1 Fast (Budget Tier):

  • Input: $0.20 per million tokens
  • Output: $0.50 per million tokens

ChatGPT 5 is 58% cheaper on input than Grok 4, and 33% cheaper on output. A request with 100K input tokens and 5K output tokens costs $0.15 on ChatGPT 5 versus $0.34 on Grok 4. The gap closes if using Grok 4.1 Fast at $0.225 per task, but Grok 4.1 is optimized for speed, not reasoning depth.

Monthly Cost at Scale

Processing 10 million tokens/month input + 2 million output:

ChatGPT 5: ($1.25 × 10M) + ($10.00 × 2M) = $12.50 + $20.00 = $32.50/month

Grok 4: ($3.00 × 10M) + ($15.00 × 2M) = $30.00 + $30.00 = $60.00/month

ChatGPT is roughly 45% cheaper at this scale. At 100M input + 20M output (typical for larger production systems):

ChatGPT 5: $125 + $200 = $325/month

Grok 4: $300 + $300 = $600/month

Grok's cost advantage shrinks as output volume grows (completion tokens cost more on Grok). ChatGPT's cheaper input rate dominates most workloads where the input-to-output ratio is high (10:1 or more).

Cost Optimization Features

xAI Batch API: Grok offers 50% discount on non-real-time workloads. Batch requests process asynchronously and cost half as much. Good for nightly data processing, scheduled analysis, and report generation. ChatGPT's batch API (available for GPT-4o) offers similar discounts but documentation is less prominent.

Prompt Caching: xAI's caching mechanism provides 50-75% discounts on repeated prompt prefixes. Systems that reuse the same system prompt or context across many requests benefit significantly. A customer support chatbot with a standard 50K token context repeated across 1,000 requests could save $1,500/month on that alone.

Subscription Tiers

ChatGPT Plus: $20/month. Includes ChatGPT 5 access, Canvas, code execution, and Sora 2 video generation. No usage limits. Good for individuals and small teams.

ChatGPT Pro: Higher tier mentioned in documentation but exact pricing not published. Production-grade features and potentially higher rate limits.

Grok SuperGrok: $30/month. Includes Grok 4 access and full X integration. Aurora image/video generation. $10 more than ChatGPT Plus.

Grok Free Tier: Grok announced free access to Grok 4.1 Fast with free credits ($25 signup bonus). Useful for evaluation and light workloads.

Context Windows

ModelContext WindowUse Cases
ChatGPT 5 (standard)272,000 tokensMost documents, long conversations
ChatGPT 5 (API extended)1,050,000 tokensFull codebases, research batches, patent prior art
Grok 4256,000 tokensMost single-document analysis
Grok 4.1 Fast2,000,000 tokensMassive batches, long conversation history

ChatGPT 5's 1.05M context window via API is 4x larger than Grok 4's 256K, though Grok 4.1 Fast introduces a 2M context option that exceeds both flagship models. The extended context matters for specific workloads.

Full codebase analysis: A single Postgres repository is typically 150K-300K tokens. An entire microservices architecture with three services is 500K-800K tokens. ChatGPT 5 or Grok 4.1 Fast handle these without splitting. Grok 4 requires chunking, losing cross-file context.

Legal discovery: A typical large-scale contract is 5K-15K tokens. Batch reviewing 50 contracts for compliance gaps is 250K-750K tokens. ChatGPT 5 and Grok 4.1 Fast process the full batch. Grok 4 caps at 256K, requiring multiple API calls and manual reassembly.

Research paper batches: Average paper is 8K-12K tokens. A researcher analyzing 40 papers totaling 320K-480K tokens fits in ChatGPT 5's extended context but exceeds Grok 4. Grok 4.1 Fast handles it with room to spare.

Patent prior art: Searching 30 patents (5K-10K tokens each) for claim overlap is 150K-300K tokens. ChatGPT 5 does it in one pass. Grok 4 requires two passes.

ChatGPT 5 on-device (non-API) context is 272K, putting it nearly on par with Grok 4 at 256K. The extended context is API-specific. Consumer users on ChatGPT Plus (capped at 272K) don't access the 1M extended window.

Benchmark Comparison

General Knowledge (MMLU)

Neither ChatGPT 5 nor Grok 4 has published official MMLU scores as of March 2026. ChatGPT 5's predecessor (GPT-4) scored 86.4% on an earlier version of the benchmark. Grok 3 scored 81.3%, but different benchmark versions are not directly comparable.

Caution: published benchmarks from different dates and versions cannot be directly compared. A 2024 Grok 3 MMLU score and a 2026 ChatGPT 5 MMLU score are measuring different test sets.

Science (GPQA Diamond)

ChatGPT 5: approximately 85% (per OpenAI's March 2026 announcement materials, though specific scores are less emphasized than in earlier releases)

Grok 4: 88% (confirmed on GPQA Diamond, graduate-level physics/chemistry/biology)

Grok 4's 3-point lead on graduate-level science questions is consistent. 88% means roughly 1 in 8 answers is wrong on PhD-level material. For patent analysis, technical due diligence, and research synthesis where expertise is critical, the gap matters. For general use, both are strong.

Mathematics (AIME 2025)

ChatGPT 5 score: not officially published

Grok 3 (predecessor): 93.3% (14 of 15 problems, pass@1)

ChatGPT 5 is expected to exceed Grok 3's performance based on overall capability gains, but the exact score has not been published. OpenAI's o3 model scores in the 95%+ range, but o3 is more expensive ($2.00/M input, $8.00/M output).

Coding (SWE-bench Verified)

ChatGPT 5: 76.3% (confirmed on SWE-bench Verified, real GitHub issue resolution)

Grok 4: No published SWE-bench Verified scores

ChatGPT 5.1 scored 76.3% on real-world code problems, production-grade performance. Grok has not published SWE-bench Verified scores for Grok 4. Without direct benchmarks, ecosystem and integration matter more than claimed capability.

Features and Capabilities

ChatGPT 5 Strengths

Canvas is the development standout. A dedicated code editor within the chat interface. Real-time collaboration, syntax highlighting for 100+ languages, diff visualization, inline execution. For developers writing code or documentation, this eliminates context switching to separate tools. Grok has no equivalent.

Code Execution runs Python in a persistent environment with package access (numpy, pandas, matplotlib, plotly). Data science workflows, quick prototyping, visualization all live inside the chat. Grok generates code but does not execute it. The ability to test code immediately is substantial for iteration speed.

Sora 2 generates video up to 60+ seconds at higher resolution than Aurora. Slower per second of output but better for high-quality deliverables. Good for content teams and creators. Grok's Aurora is faster for quick iterations.

Ecosystem integration is deeply established. GitHub Copilot compatibility, existing CI/CD pipelines, OpenAI API in most AI frameworks. Switching costs to Grok are real for dev teams already invested in ChatGPT.

Grok 4 Strengths

Science reasoning edges out ChatGPT on GPQA Diamond (88% vs 85%). That 3-point gap matters for patent analysis, technical research synthesis, and specialized domains where PhD-level accuracy is non-negotiable.

DeepSearch chains multi-step reasoning with web search and X data integration. Automated research agent behavior. Useful for trend analysis, market intelligence, and complex multi-source questions. ChatGPT's browsing tool is more primitive and slower.

Aurora for image and video generation. Integrated, no separate API. xAI reported 1.2 billion videos generated in January 2026, suggesting production-grade infrastructure.

Real-time X data is native and fast. Grok pulls from X's live feed without browsing tool latency. For social media monitoring, trend tracking, breaking news queries, this is meaningfully faster than ChatGPT's browsing approach.

Grok 4.1 Fast offers a budget option. $0.20/M input and $0.50/M output makes Grok competitive on cost for non-reasoning tasks. With a 2M context window, it's an economical choice for massive document processing.

Model Variants and Use Cases

ChatGPT 5 Variants

The ChatGPT 5 family currently consists of:

  • ChatGPT 5 (flagship): Full capabilities, highest cost
  • ChatGPT 5.1 (faster variant): Optimized for throughput, slightly lower latency
  • ChatGPT 5 Pro: Not yet fully detailed in public docs as of March 2026

Grok Model Variants

Grok offers more granular choices:

  • Grok 4 (flagship): Full reasoning, 256K context, $3/$15 per million tokens
  • Grok 4.1 Fast (budget/speed): 2M context, $0.20/$0.50, optimized for throughput
  • Grok 3 (legacy): Older model, cheaper, for teams not needing Grok 4 performance

The Grok 4.1 Fast variant is particularly useful for teams that need massive context windows but can tolerate slightly lower reasoning capability. At 2M tokens context, it handles virtually any document set a single request can hold.

Real-World Cost Scenarios

Scenario 1: Chatbot for Customer Support

Assumptions:

  • 500 customer queries/day
  • 300 input tokens (customer message) + 200 output tokens (response) per query
  • 30 days/month
  • Non-reasoning task

Monthly volume: 500 × 30 = 15,000 queries

  • Input: 300 × 15,000 = 4.5M tokens
  • Output: 200 × 15,000 = 3M tokens

ChatGPT 5 cost: ($1.25 × 4.5M) + ($10.00 × 3M) = $5.625 + $30 = $35.625/month

Grok 4 cost: ($3.00 × 4.5M) + ($15.00 × 3M) = $13.50 + $45 = $58.50/month

Grok 4.1 Fast cost: ($0.20 × 4.5M) + ($0.50 × 3M) = $0.90 + $1.50 = $2.40/month

ChatGPT 5 is competitive. Grok 4.1 Fast is dramatically cheaper for straightforward customer support. This workload doesn't need reasoning, so the budget model wins decisively.

Scenario 2: Code Review and Analysis

Assumptions:

  • 20 code review requests/month
  • 5K input tokens (code + context) per review
  • 1K output tokens (review feedback) per review
  • Reasoning task, benefits from deeper analysis

Monthly volume:

  • Input: 5K × 20 = 100K tokens
  • Output: 1K × 20 = 20K tokens

ChatGPT 5 cost: ($1.25 × 0.1M) + ($10.00 × 0.02M) = $0.125 + $0.20 = $0.325/month

Grok 4 cost: ($3.00 × 0.1M) + ($15.00 × 0.02M) = $0.30 + $0.30 = $0.60/month

Grok 4.1 Fast cost: ($0.20 × 0.1M) + ($0.50 × 0.02M) = $0.02 + $0.01 = $0.03/month

At this scale, cost differences are negligible in absolute terms. The decision factors are capability and context window. ChatGPT 5's 1M extended context can review an entire codebase. Grok 4.1 Fast can handle 2M context. Grok 4's 256K context requires multiple passes.

Assumptions:

  • 50 contracts/month
  • 10K tokens per contract (full document)
  • 500 output tokens per analysis
  • Reasoning task (checking compliance, identifying risks)

Monthly volume:

  • Input: 10K × 50 = 500K tokens
  • Output: 500 × 50 = 25K tokens

ChatGPT 5 cost: ($1.25 × 0.5M) + ($10.00 × 0.025M) = $0.625 + $0.25 = $0.875/month

Grok 4 cost: ($3.00 × 0.5M) + ($15.00 × 0.025M) = $1.50 + $0.375 = $1.875/month

With batch API (50% discount on Grok): Grok 4 batch: $1.875 × 0.5 = $0.9375/month

Again negligible in absolute terms. ChatGPT 5's 1M context can process all 50 contracts in a single request. Grok 4 requires two passes (256K limit). Grok batch API reduces per-request cost but increases latency (async processing). For compliance-critical work, ChatGPT 5 is more practical.

Integration and Ecosystem

ChatGPT 5 Ecosystem

GitHub Copilot: Native integration. Developers using Copilot for code completion have ChatGPT 5 as the backend. Deep IDE integration. Autocomplete, code generation, test writing all flow through ChatGPT 5.

OpenAI API: Stable API with comprehensive SDKs (Python, Node.js, Go, etc.). Used by most AI frameworks (LangChain, LlamaIndex, Vercel AI SDK). Ecosystem depth means ChatGPT integrates into most production systems without custom development.

Canvas: Dedicated editor for long-form content. Real-time collaboration, version history, export to markdown, PDF, or HTML. No equivalent on Grok side.

ChatGPT for Enterprise: SOC 2 Type II certified. HIPAA-eligible plans available. FedRAMP in process. Regulatory teams already know how to use ChatGPT in compliance contexts.

Grok Ecosystem

X Integration: Direct connection to X's platform. Real-time trending topics, social listening, customer sentiment analysis all available natively. No browsing latency.

xAI Partners: Grok is available through Together.AI and other inference platforms, though pricing is typically higher than direct API.

Aurora Integration: Native image and video generation. xAI positions this as a fully integrated creative platform rather than separate tools.

Free Tier Access: Free Grok 4.1 Fast with $25 credits and additional grants available. Lower barrier to entry for teams evaluating Grok.

Use Case Recommendations

ChatGPT 5 fits better for:

Development teams already in the OpenAI stack. Canvas, code execution, GitHub Copilot integration, and existing API usage mean staying with ChatGPT is the path of least resistance. Switching costs outweigh marginal capability differences.

Long-context document analysis. Codebase refactoring, legal discovery, patent prior-art searches, and full-repo code review all benefit from the 1.05M context window. Grok 4's 256K ceiling requires splitting documents across multiple requests, losing cross-document context.

Cost-sensitive API workloads. ChatGPT 5 at $1.25/$10 is 58% cheaper on input than Grok 4. For high-volume batch processing, the savings compound. At 100M tokens/month, that's $275/month savings over Grok 4.

Regulated industries. ChatGPT has SOC 2 Type II, HIPAA BAAs, FedRAMP authorization. Healthcare, finance, and government teams default to OpenAI.

Grok 4 fits better for:

Science and technical reasoning where the 3-point GPQA Diamond lead translates to fewer errors on expert-level questions. Patent analysis, research synthesis, technical due diligence.

Real-time queries about breaking news, social trends, or current events. Grok's native X feed integration returns current data faster than ChatGPT's browsing tool.

Content creators needing integrated image and video generation without API context switching.

Cost optimization via Grok 4.1 Fast. For non-reasoning workloads, the $0.20/$0.50 pricing is aggressively low. Customer support, content tagging, data extraction all benefit.

Massive context windows. Grok 4.1 Fast's 2M context handles scenarios that exceed ChatGPT 5's 1M API limit. Rare, but when needed, it's essential.

FAQ

Which is cheaper, ChatGPT 5 or Grok 4? ChatGPT 5 is cheaper on standard pricing: $1.25 vs $3.00/M input, $10 vs $15/M output. Roughly 45% cheaper on a typical workload. Grok 4.1 Fast undercuts both at $0.20/$0.50 for non-reasoning tasks. For subscriptions, ChatGPT Plus at $20/mo beats SuperGrok at $30/mo.

What's the context window difference? ChatGPT 5 API: 1.05M tokens (extended). Grok 4: 256K. Grok 4.1 Fast: 2M. ChatGPT 5 is best for general use. Grok 4.1 Fast is best for massive batches. For standard documents under 250K, all three work.

Which is better for coding? ChatGPT 5 due to Canvas, code execution, and ecosystem depth. Both generate code competently. Canvas eliminates context switching and enables real-time collaboration. GitHub Copilot integration is ChatGPT-native.

Which is better for long-context analysis? ChatGPT 5 API at 1.05M tokens, or Grok 4.1 Fast at 2M tokens. Standard Grok 4 is limiting at 256K.

Is the 88% vs 85% science score gap meaningful? On PhD-level questions (GPQA Diamond), yes. 3 points means 1 in 8 answers differs. For domain-critical work (patent analysis, research synthesis), the gap matters. For general use, both are strong.

Can both be used together? Yes. Route long-context work and cost-sensitive batch jobs to ChatGPT 5, science-heavy reasoning to Grok 4, high-volume non-reasoning to Grok 4.1 Fast. All expose standard APIs. Hybrid routing is viable for large teams.

Should we migrate from ChatGPT to Grok? Only if your use cases are heavy on science reasoning and real-time data. For most teams, ChatGPT's ecosystem depth and established integration make it the lower-risk choice. New projects can evaluate Grok in parallel.

What about Grok 4.1 Fast vs ChatGPT 5? For cost-sensitive, non-reasoning workloads, Grok 4.1 Fast is dramatically cheaper. For reasoning, code, or regulated industries, ChatGPT 5. The comparison is use-case specific.

Sources