GPT-5.6 Sol vs Grok 4.5
Pricing & Specs

OpenAI vs xAI, side by side from a live registry. Specs below, then benchmark both on your own task.

$30
GPT-5.6 Sol output / 1M
$6
Grok 4.5 output / 1M
1.05M / 500K
context windows

TL;DR: On a typical task (1K input + 500 output tokens), Grok 4.5 is about 4.0x cheaper than GPT-5.6 Sol. But per-token price is not cost per result: a cheaper model that needs more tokens, retries, or hand-holding can end up more expensive on your workload. The specs below are facts; which one is better at YOUR task is measurable, not guessable.

API Pricing: GPT-5.6 Sol vs Grok 4.5

TokensGPT-5.6 SolGrok 4.5
Input$5 / 1M$2 / 1M
Output$30 / 1M$6 / 1M
Cached input$0.5 / 1M$0.3 / 1M

What that means in practice (1K input + 500 output tokens)

1x One typical task: $0.0200 on GPT-5.6 Sol vs $0.0050 on Grok 4.5
1K 1,000 runs: $20.00 vs $5.00
💡 Real cost depends on how verbose each model is on YOUR prompts. Benchmark to measure actual tokens, not estimates.

Specs Compared

SpecGPT-5.6 SolGrok 4.5
Context window1.05M tokens500K tokens
Max output tokens128K tokens-
Input modalitiestext, imagetext, image
Knowledge cutoffFebruary 16, 2026-
Latency (measured)--
Reasoning modelYesYes
Tool / function callingYesYes
JSON modeYesYes
Prompt cachingYesYes

When to Choose Which

High volume on a budget: start with Grok 4.5; only pay for GPT-5.6 Sol if the benchmark shows a quality gap that matters.
Long documents or big codebases: GPT-5.6 Sol has the larger context window (1.05M vs 500K tokens).
Everything else: the honest answer is to benchmark both on your actual task. Quality differences are task-specific and shift with every release.

FAQ

Which is cheaper, GPT-5.6 Sol or Grok 4.5?

GPT-5.6 Sol costs $5/$30 per 1M input/output tokens; Grok 4.5 costs $2/$6. On a typical task (1K input + 500 output tokens), Grok 4.5 is about 4.0x cheaper than GPT-5.6 Sol.

Which has the bigger context window, GPT-5.6 Sol or Grok 4.5?

GPT-5.6 Sol has a 1.05M-token context window; Grok 4.5 has 500K tokens.

Is GPT-5.6 Sol better than Grok 4.5?

It depends on the task. Generic leaderboards won't tell you which one wins on YOUR workload. OpenMark lets you benchmark GPT-5.6 Sol and Grok 4.5 head to head on your own task with real API calls, no API keys needed, free tier available.

GPT-5.6 Sol or Grok 4.5 for YOUR Task?

Spec tables can't answer that. Run both head to head on your actual workload:
real API calls, ranked results with accuracy, cost, and latency. Free tier available.

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