GPT-5.5 Pro vs Grok 4.20 Multi Agent
At a Glance
| Compare |  GPT-5.5 ProOpenAI | |
|---|---|---|
| Intelligence, Cost, and Efficiency | ||
| IntelligenceHigher is better · MM Intelligence v2.5 | UnrankedNot in the 46-model eligible cohort | #22 of 4663.4 score · 2/3 sources · provisional · missing LiveBench · full-core range 42.3–75.6 |
| Pricing and Limits | ||
| Input priceFrom · USD / 1M tokens | $30.00Openai ↗ · Sep 3, 2026 | $1.25Xai ↗ · Sep 3, 2026 |
| Output priceFrom · USD / 1M tokens | $180.00Openai ↗ · Sep 3, 2026 | $2.50Xai ↗ · Sep 3, 2026 |
| Context windowMaximum documented tokens | 1,050K | 1,000K |
| Model facts checked | Sep 3, 2026View model evidence → | Aug 29, 2026View model evidence → |
Token prices are the lowest available sourced USD rates; input and output may use different providers. Cost ranking estimates output spend on LiveBench, not a full request bill. Ranking methodology →
Available Benchmarks
| Benchmark | GPT-5.5 Pro | Grok 4.20 Multi-Agent |
|---|---|---|
| ARC-AGI-1verified-v1-ba05d69f6453 · verified_score · leader | 96.50100% of row best · percent · GPT-5.5 Pro (High) | 89.5093% of row best · percent · Grok 4.20 (Reasoning) |
| ARC-AGI-2verified-v2-6c676fa3e9af · verified_score · leader | 84.58100% of row best · percent · GPT-5.5 Pro (High) | 65.1477% of row best · percent · Grok 4.20 (Reasoning) |
| Overall ResultCounted from the protocol-matched rows above | 2 benchmark winsNo overall winner | 0 benchmark winsNo overall winner |
Third-party benchmark Only like-for-like primary-publisher results are shown; raw scores, relative scores, configuration, and token spend remain visible.
Side-by-Side Facts
| Field | GPT-5.5 Pro | Grok 4.20 Multi-Agent |
|---|---|---|
| Developer | OpenAI | xAI |
| Family | Gpt 5 5 | Grok 4 20 |
| Model | GPT-5.5 Pro | Grok 4.20 Multi-Agent |
| Version | GPT-5.5 Pro | Grok 4.20 Multi-Agent |
| Lifecycle | active | preview |
| Released | 2026-04-23 | Unknown |
| Knowledge cutoff | 2025-12-01 | Unknown |
| Input modalities | Text, Image | Text, Image |
| Output modalities | Text | Text |
| Context window | 1,050K | 1,000K |
| Total parameters | Unknown | Unknown |
| Active parameters | Unknown | Unknown |
| License | Unknown | Unknown |
| Open weights | No | No |
| API available | Yes | Yes |
| Self-hostable | No | No |
| Provider access | Openai (Standard), Openrouter (Standard) | Xai (Standard) |
| Capabilities | chat, generation, reasoning, structured_outputs, tools | generation, reasoning, research, tools |
GPT-5.5 Pro Capabilities
Grok 4.20 Multi Agent Capabilities
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Primary Evidence
Sources and Freshness
Questions
GPT-5.5 Pro vs Grok 4.20 Multi Agent FAQs
Is GPT-5.5 Pro or Grok 4.20 Multi Agent better for coding?+
This comparison does not currently contain a protocol-matched coding benchmark for both GPT-5.5 Pro and Grok 4.20 Multi Agent, so Model Markets cannot name a coding leader from pricing, context size, or capability labels alone.
Which is cheaper, GPT-5.5 Pro or Grok 4.20 Multi Agent?+
GPT-5.5 Pro is $30.00 and Grok 4.20 Multi Agent is $1.25 per million tokens, so Grok 4.20 Multi Agent is cheaper on this metric. GPT-5.5 Pro is $180.00 and Grok 4.20 Multi Agent is $2.50 per million tokens, so Grok 4.20 Multi Agent is cheaper on this metric.
Which has a larger context window, GPT-5.5 Pro or Grok 4.20 Multi Agent?+
GPT-5.5 Pro has the larger sourced context window. GPT-5.5 Pro supports 1,050K and Grok 4.20 Multi Agent supports 1,000K.
Which performs better in benchmarks, GPT-5.5 Pro or Grok 4.20 Multi Agent?+
There is no overall benchmark winner: An overall winner requires at least two decisive benchmarks from at least two original publishers.
Can GPT-5.5 Pro or Grok 4.20 Multi Agent be self-hosted?+
Both models have the same recorded self-hosting status: unsupported. GPT-5.5 Pro is not marked open weight; Grok 4.20 Multi Agent is not marked open weight.
Can GPT-5.5 Pro and Grok 4.20 Multi Agent understand images?+
GPT-5.5 Pro is documented with image input; Grok 4.20 Multi Agent is documented with image input. This reflects supported input modalities, not vision quality.
Which can generate longer answers, GPT-5.5 Pro or Grok 4.20 Multi Agent?+
Neither has a larger sourced maximum output. GPT-5.5 Pro is 128K and Grok 4.20 Multi Agent is —.
Do GPT-5.5 Pro and Grok 4.20 Multi Agent support reasoning and tool use?+
GPT-5.5 Pro: reasoning, tool calling, and image input. Grok 4.20 Multi Agent: reasoning, tool calling, and image input. Feature support does not establish relative quality.
Which is available from more inference providers, GPT-5.5 Pro or Grok 4.20 Multi Agent?+
GPT-5.5 Pro has 2 sourced provider routes; Grok 4.20 Multi Agent has 1, so GPT-5.5 Pro has broader tracked availability.
Which offers better value, GPT-5.5 Pro or Grok 4.20 Multi Agent?+
There is no universal value winner. Compare the input and output prices above with the matched benchmark result for your workload: cheaper tokens can be offset by different quality, token usage, latency, or provider availability.