GPT-5.5 vs Grok 4.20 Multi-Agent
Benchmark Performance
Available Benchmarks
| Benchmark | GPT-5.5 | Grok 4.20 Multi-Agent |
|---|---|---|
| ARC-AGI-1verified-v1-15fb467fd4fc · verified_score · leader | 95.00100% of row best · percent · GPT-5.5 (XHigh) | 89.5094% of row best · percent · Grok 4.20 (Reasoning) |
| ARC-AGI-2verified-v2-9a3db289984e · verified_score · leader | 85.00100% of row best · percent · GPT-5.5 (XHigh) | 65.1477% of row best · percent · Grok 4.20 (Reasoning) |
| LMArena Search Arenasearch-2026-08-24-011508720696 · arena_rating · leader | 1,242.05100% of row best · rating · gpt-5.5-search; 95% CI [1236.73488085, 1247.37053078]; votes 89873; rank 3 | 1,204.1197% of row best · rating · grok-4.20-multi-agent-beta-0309; 95% CI [1198.80874858, 1209.41102574]; votes 109553; rank 13 |
| LMArena Text Arenatext-2026-09-01-011508720696 · arena_rating · leader | 1,466.80100% of row best · rating · gpt-5.5; 95% CI [1462.99653821, 1470.60035247]; votes 64686; rank 27 | 1,450.2299% of row best · rating · grok-4.20-multi-agent-beta-0309; 95% CI [1446.44654530, 1453.99996127]; votes 60845; rank 43 |
| LMArena Vision Arenavision-2026-08-27-011508720696 · arena_rating · leader | 1,294.36100% of row best · rating · gpt-5.5-high; 95% CI [1287.65516407, 1301.05910249]; votes 20121; rank 18 | 1,259.9797% of row best · rating · grok-4.20-multi-agent-beta-0309; 95% CI [1253.56879963, 1266.36768970]; votes 22988; rank 42 |
| Overall ResultCounted from the protocol-matched rows above | 5 benchmark winsOverall lead | 0 benchmark wins |
Third-party benchmark Only like-for-like primary-publisher results are shown; raw scores, relative scores, configuration, and token spend remain visible.
Technical Differences
Side-by-Side Facts
| Field | GPT-5.5 | Grok 4.20 Multi-Agent |
|---|---|---|
| Developer | Openai | Xai |
| Family | Gpt 5 5 | Grok 4 20 |
| Model | GPT-5.5 | Grok 4.20 Multi-Agent |
| Version | GPT-5.5 | Grok 4.20 Multi-Agent |
| Lifecycle | active | preview |
| Released | 2026-04-23 | Unknown |
| Knowledge cutoff | 2025-12-01 | Unknown |
| Input modalities | Unknown | Unknown |
| Output modalities | Unknown | Unknown |
| Context window | 1,050,000 | 1,000,000 |
| 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 |
11 comparable fields · 8 material differences · Interactive comparison only; indexing gate not met
GPT-5.5 Capabilities
Grok 4.20 Multi-Agent Capabilities
Primary Evidence
Sources and Freshness
Questions
GPT-5.5 vs Grok 4.20 Multi-Agent FAQs
Is GPT-5.5 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 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 or Grok 4.20 Multi-Agent?+
Only GPT-5.5 has a directly sourced input price: $5.00 per million tokens. Only GPT-5.5 has a directly sourced output price: $30.00 per million tokens.
Which has a larger context window, GPT-5.5 or Grok 4.20 Multi-Agent?+
GPT-5.5 has the larger sourced context window. GPT-5.5 supports 1,050,000 and Grok 4.20 Multi-Agent supports 1,000,000.
Which performs better in benchmarks, GPT-5.5 or Grok 4.20 Multi-Agent?+
GPT-5.5 leads the current overall benchmark count. The result uses 5 protocol-matched benchmarks from 2 publishers; it is not a universal quality score.
Can GPT-5.5 or Grok 4.20 Multi-Agent be self-hosted?+
Both models have the same recorded self-hosting status: unsupported. GPT-5.5 is not marked open weight; Grok 4.20 Multi-Agent is not marked open weight.
Can GPT-5.5 and Grok 4.20 Multi-Agent understand images?+
GPT-5.5 is not documented with image input; Grok 4.20 Multi-Agent is not documented with image input. This reflects supported input modalities, not vision quality.
Which can generate longer answers, GPT-5.5 or Grok 4.20 Multi-Agent?+
Neither has a larger sourced maximum output. GPT-5.5 is 128,000 and Grok 4.20 Multi-Agent is —.
Do GPT-5.5 and Grok 4.20 Multi-Agent support reasoning and tool use?+
GPT-5.5: reasoning and tool calling. Grok 4.20 Multi-Agent: reasoning and tool calling. Feature support does not establish relative quality.
Which is available from more inference providers, GPT-5.5 or Grok 4.20 Multi-Agent?+
GPT-5.5 has 2 sourced provider routes; Grok 4.20 Multi-Agent has 1, so GPT-5.5 has broader tracked availability.
Which offers better value, GPT-5.5 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.