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Head-to-head comparison

GPT-5.2 Chat vs Grok 4.5

GPT-5.2 Chat (OpenAI) and Grok 4.5 (xAI) compared on the ModelCap Index, API price, context window, provider availability, weight access and every public benchmark board they share. Figures are the same ones shown on the live rankings; nothing here is a hidden score.

Snapshot as of 11 August 2026

As of 11 August 2026, GPT-5.2 Chat holds the stronger ModelCap Index position (#9 vs #12); Grok 4.5 is 2.3× cheaper per output token ($6.00/1M vs $14.00/1M); and Grok 4.5 offers the longer context window (500K vs 128K tokens).

Which should you choose?

Choose GPT-5.2 Chat if…

  • you want the stronger overall ModelCap Index position — #9 against #12 (74.1 vs 70.7 points).
  • your workload is prompt-heavy — input tokens cost $1.75/1M against $2.00/1M.
  • Arena text is your yardstick — 1476 against 1469.

Choose Grok 4.5 if…

  • API cost matters — $6.00/1M output tokens against $14.00/1M, about 2.3× cheaper.
  • you need the longer context window — 500K tokens against 128K.
  • Arena coding is your yardstick — 1522 against 1515.
  • you want the more recently listed model — Grok 4.5 was listed 8 July 2026, GPT-5.2 Chat 10 December 2025.

GPT-5.2 Chat vs Grok 4.5: specs, pricing and context

Specification comparison of GPT-5.2 Chat and Grok 4.5
FieldGPT-5.2 ChatOpenAIGrok 4.5xAI
ModelCap Index position#9#12
Index score74.170.7
EvidenceMeasuredMeasured
Input price / 1M tokens$1.75$2.00
Output price / 1M tokens$14.00$6.00
Context window128K tokens500K tokens
Max output tokens32K—
API providers listed11
Weight accessAPI onlyAPI only
Input modalitiesFile, Image, TextText, Image, File
First listed10 December 20258 July 2026
PublisherOpenAIxAI

Evidence: 2 public benchmark observations across 2 boards · 5 public benchmark observations across 5 boards. Prices are the lowest listed API offer per million tokens observed on the OpenRouter catalogue.

Benchmark scores: GPT-5.2 Chat vs Grok 4.5

Public benchmark boards where GPT-5.2 Chat or Grok 4.5 has a published result
BoardGPT-5.2 ChatGrok 4.5Leads
Arena textArena (LMArena)14761472–148014691464–1475GPT-5.2 Chat
Arena codingArena (LMArena)15151508–152215221513–1531Grok 4.5
LMArena AgentLMArena—5.6%4.3%–6.8%Only one result
ARC-AGI-2ARC Prize Foundation—52.6%HighOnly one result
ARC-AGI-3ARC Prize Foundation—0.3%MediumOnly one result

Scores are the sources' own published figures for each model's best evaluated configuration; ModelCap never re-runs a benchmark.

Want a different pairing? Open the interactive comparison tool to swap either model for any current ranked language model.

GPT-5.2 Chat vs Grok 4.5: common questions

Is GPT-5.2 Chat better than Grok 4.5?

GPT-5.2 Chat ranks higher on the ModelCap Index as of 11 August 2026: #9 against #12. That is a capability ranking built from public benchmark evidence with published uncertainty; whether it is "better" for you also depends on price, context and where you can run it.

Is GPT-5.2 Chat cheaper than Grok 4.5?

Grok 4.5 is cheaper on output tokens: $6.00/1M against $14.00/1M. Input tokens are $1.75/1M for GPT-5.2 Chat and $2.00/1M for Grok 4.5. Prices are the lowest listed API offer ModelCap observed, in USD per million tokens.

Which has the bigger context window, GPT-5.2 Chat or Grok 4.5?

Grok 4.5 has the larger context window: 500K tokens against 128K.

Which is better for coding, GPT-5.2 Chat or Grok 4.5?

Arena coding: GPT-5.2 Chat 1515, Grok 4.5 1522 — Grok 4.5 leads.

Are GPT-5.2 Chat and Grok 4.5 open-weight models?

GPT-5.2 Chat: API only. Grok 4.5: API only. Open weights mean the checkpoint can be downloaded and self-hosted under its licence; API-only models are available solely through hosted endpoints.

Where can I run GPT-5.2 Chat and Grok 4.5?

ModelCap currently lists 1 API provider for GPT-5.2 Chat and 1 for Grok 4.5, from the OpenRouter catalogue snapshot the site serves; each model page lists the providers and their prices.

How current is this GPT-5.2 Chat vs Grok 4.5 comparison?

Every figure comes from the sealed ModelCap dataset published 11 August 2026; the page re-renders within a minute of each data refresh, and the ModelCap Index positions are the same ones shown on the live rankings.

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