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GPT-5.6 Sol vs Grok 4.20

GPT-5.6 Sol

OpenAI

89#21
vs
Grok 4.20

xAI

88#22
Signal-by-Signal Comparison
SignalGPT-5.6 SolDeltaGrok 4.20
Capabilities
100
--
100
Benchmarks
88
+1
86
Pricing
70
-27
98
Context window size
86
-4
90
Recency
100
--
100
Output Capacity
85
+65
20
Overall Result
2 wins
of 6
2 wins
It's a tie - both models win 2 signals each

Score History

Score History (15 data points)
GPT-5.6 SolGrok 4.20
GPT-5.6 Sol

88.5

current score

Leader

GPT-5.6 Sol

right now

Grok 4.20

88.3

current score

LMMarketCap.com
Interactive Price Comparison
100Kcalls/month
1,000tokens (~1,333 chars)
500tokens (~667 chars)

GPT-5.6 Sol

OpenAI

Per request$0.020000
Daily$66.67
Monthly$2000.00
Annual$24000.00

Grok 4.20

xAI

Best Value
Per request$0.002500
Daily$8.33
Monthly$250.00
Annual$3000.00

Grok 4.20 saves you $1750.00/month

That's $21000.00/year compared to GPT-5.6 Sol at your current usage level of 100K calls/month.

88% cheaper
Choose Grok 4.20 for cost optimization

GPT-5.6 Sol pricing:
Input:$5.00/M tokens
Output:$30.00/M tokens
Grok 4.20 pricing:
Input:$1.25/M tokens
Output:$2.50/M tokens
Winner
GPT-5.6 Sol

OpenAI

89

Composite Score

Grok 4.20

xAI

88

Composite Score

Signal-by-Signal Comparison
MetricGPT-5.6 SolGrok 4.20Winner
Overall Score
89
88
GPT-5.6 Sol
Rank#21#22
GPT-5.6 Sol
Quality Rank#21#22
GPT-5.6 Sol
Adoption Rank#21#22
GPT-5.6 Sol
Parameters------
Context Window1050K2000K
Grok 4.20
Pricing$5.00/$30.00/M$1.25/$2.50/M--
Signal Scores
Capabilities
100
100
GPT-5.6 Sol
Benchmarks
88
86
GPT-5.6 Sol
Pricing
70
98
Grok 4.20
Context window size
86
90
Grok 4.20
Recency
100
100
GPT-5.6 Sol
Output Capacity
85
20
GPT-5.6 Sol
Benchmark Head-to-Head(12 benchmarks)
GPT-5.6 Sol: 9Grok 4.20: 1
GPT-5.6 Sol
Grok 4.20
Normalized 0-100%
MMLU
93%91.5%
MMLU-Pro
84.5%83.5%
GPQA Diamond
85%82%
MATH-500
92.5%95%
HumanEval
96.5%95.5%
SWE-bench Verified
75%70%
AIME 2024
-88%
IFEval
92%91%
BBH
90.5%90%
Arena Elo
14651462
LiveBench
76%73%
HLE
35%-
Benchmark Interpretation

Our score (0-100) is driven by benchmark performance (90%) from Arena Elo ratings, MMLU, GPQA, HumanEval, SWE-bench, and 15+ standardized evaluations. Capabilities and context window serve as tiebreakers (10%). Learn more about our methodology.

GPT-5.6 SolElite Tier

Scores 89/100 (rank #21), placing it in the top 93% of all 290 models tracked.

Raw Quality0/100
Cost Efficiency0/100
Speed0/100
Grok 4.20Elite Tier

Scores 88/100 (rank #22), placing it in the top 93% of all 290 models tracked.

Raw Quality0/100
Cost Efficiency0/100
Speed0/100

With only a 0-point gap, these models are in the same performance tier. The practical difference in output quality is minimal - your choice should depend on pricing, latency requirements, and specific feature needs.

When to Use Each Model

Choose GPT-5.6 Sol when you need:

  • Step-by-step reasoning and chain-of-thought problem solving

Choose Grok 4.20 when you need:

  • High-volume production workloads where API costs must be minimized
  • Processing long documents or large codebases (2000K token context)
  • Step-by-step reasoning and chain-of-thought problem solving
Cost-Performance Analysis
GPT-5.6 Sol
Input cost$5.00/M tokens
Output cost$30.00/M tokens
Cost per quality point$0.395
Est. monthly (1M tokens/day)$525.00
Grok 4.20Best Value
Input cost$1.25/M tokens
Output cost$2.50/M tokens
Cost per quality point$0.042
Est. monthly (1M tokens/day)$56.25

Grok 4.20 offers 89% better value per quality point. At 1M tokens/day, you'd spend $56.25/month with Grok 4.20 vs $525.00/month with GPT-5.6 Sol - a $468.75 monthly difference.

Latency & Speed
GPT-5.6 SolFaster
Speed score0/100
Grok 4.20
Speed score0/100

Both models have comparable response speeds. For most applications, the latency difference is negligible.

When latency matters most: Interactive chatbots, IDE code completion, real-time translation, and user-facing applications where response time directly impacts experience. For batch processing, background summarization, or offline analysis, latency is less critical.

Example Use Cases

Code generation & review

Based on overall model capabilities and architecture for coding tasks like generating functions, debugging, and refactoring

GPT-5.6 Sol

Customer support chatbot

Suitable for user-facing chat with competitive response times. Grok 4.20 also offers lower per-token costs for high-volume support

GPT-5.6 Sol

Long document analysis

Larger context window (2000K tokens) can process longer documents, contracts, and research papers in a single pass

Grok 4.20

Batch data extraction

Lower output pricing ($2.50/M) reduces costs when processing thousands of records daily

Grok 4.20

Creative writing & content

Higher overall composite score (89/100) correlates with better nuance, coherence, and style in long-form content

GPT-5.6 Sol

Image understanding & OCR

Supports vision input - can analyze screenshots, diagrams, photos, and scanned documents directly

GPT-5.6 Sol
Which Should You Choose?
Our recommendation:
GPT-5.6 Sol

GPT-5.6 Sol and Grok 4.20 are extremely close in overall performance (only 0.20000000000000284 points apart). Your best choice depends entirely on which specific strengths matter most for your use case.

GPT-5.6 Sol
Recommended

by OpenAI

  • Choose for Quality - Marginally better benchmark scores; both are excellent
  • Choose for Reliability - Higher uptime and faster response speeds
  • Choose for Prototyping - Stronger community support and better developer experience
  • Choose for Production - Wider enterprise adoption and proven at scale

by xAI

  • Choose for Cost - 89% lower pricing; better value at scale
Capability Comparison
CapabilityGPT-5.6 SolGrok 4.20
Vision (Image Input)
Function Calling
Streaming
JSON Mode
Reasoning
Web Search
Image Output
Monthly Cost Calculator
1,000tokens (600 in / 400 out)
100requests/day (3,000/month)

GPT-5.6 Sol

OpenAI

$45.00
estimated monthly cost

Grok 4.20

xAI

Best Value
$5.25
estimated monthly cost

Grok 4.20 saves you $39.75/month

That's 88% cheaper than GPT-5.6 Sol at 1,000 tokens/request and 100 requests/day.

Assumes 60% input / 40% output token ratio per request. Actual costs may vary based on your usage pattern.

Parameters & Context
ParameterGPT-5.6 SolGrok 4.20
Context Window1.1M2M
Max Output Tokens128,000--
Open SourceNoNo
CreatedJul 9, 2026Mar 31, 2026
Last updated: 14m ago

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GPT-5.6 Sol vs Grok 4.20 (2026) | LM Market Cap