Head-to-head comparison
Gemini 3.5 Flash Lite (Google) and Grok 4.20 Multi-Agent (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 30 September 2026
As of 30 September 2026, Grok 4.20 Multi-Agent holds the stronger ModelCap Index position (#14 vs #29); and Grok 4.20 Multi-Agent offers the longer context window (2M vs 1M tokens).
Evidence: 4 public benchmark observations across 4 boards · 2 public benchmark observations across 2 boards. Prices are the lowest listed API offer per million tokens observed on the OpenRouter catalogue.
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.
Grok 4.20 Multi-Agent ranks higher on the ModelCap Index as of 30 September 2026: #14 against #29. 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. Their published uncertainty intervals overlap, so the rank difference alone does not establish a reliable capability advantage for your workload.
Both list the same output price, $2.50/1M tokens, with input at $0.30/1M and $1.25/1M respectively. For 1,000 requests with 2,000 input and 500 output tokens each (2M input + 0.5M output), the listed-rate estimate is $1.85 for Gemini 3.5 Flash Lite versus $3.75 for Grok 4.20 Multi-Agent. Gemini 3.5 Flash Lite costs 50.7% less in this scenario. This excludes caching, batch discounts, prompt-length tiers, tool charges and retries; verify the selected endpoint before budgeting.
Grok 4.20 Multi-Agent has the larger context window: 2M tokens against 1M.
Arena coding: Gemini 3.5 Flash Lite 1503, Grok 4.20 Multi-Agent 1508 — Grok 4.20 Multi-Agent leads.
Gemini 3.5 Flash Lite: API only. Grok 4.20 Multi-Agent: 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.
ModelCap currently lists 2 API providers for Gemini 3.5 Flash Lite and 1 for Grok 4.20 Multi-Agent, from the OpenRouter catalogue snapshot the site serves; each model page lists the providers and their prices.
Every figure and ModelCap Index position comes from the same published snapshot dated 30 September 2026. Publication and page updates happen separately; use the snapshot date shown on the page.