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Head-to-head comparison

Gemma 4 31B vs Grok 4.20 Multi-Agent

Gemma 4 31B (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 22 September 2026

As of 22 September 2026, Grok 4.20 Multi-Agent holds the stronger ModelCap Index position (#18 vs #29); Gemma 4 31B is 7.4× cheaper per output token ($0.34/1M vs $2.50/1M); Grok 4.20 Multi-Agent offers the longer context window (2M vs 262K tokens); and Gemma 4 31B ships open weights.

Which should you choose?

Choose Gemma 4 31B if…

  • API cost matters — $0.34/1M output tokens against $2.50/1M, about 7.4× cheaper.
  • your workload is prompt-heavy — input tokens cost $0.09/1M against $1.25/1M.
  • you want to self-host: Gemma 4 31B ships open weights while Grok 4.20 Multi-Agent is api only.
  • you want provider choice — 11 listed API providers against 1.
  • you want the more recently listed model — Gemma 4 31B was listed 2 April 2026, Grok 4.20 Multi-Agent 31 March 2026.

Choose Grok 4.20 Multi-Agent if…

  • you want the stronger overall ModelCap Index position — #18 against #29 (81.2 vs 73.8 points).
  • you need the longer context window — 2M tokens against 262K.
  • Arena coding is your yardstick — 1508 against 1499.

Gemma 4 31B vs Grok 4.20 Multi-Agent: specs, pricing and context

Specification comparison of Gemma 4 31B and Grok 4.20 Multi-Agent
FieldGemma 4 31BGoogleGrok 4.20 Multi-AgentxAI
ModelCap Index position#29#18
Index score73.881.2
EvidenceMeasuredMeasured
Input price / 1M tokens$0.09$1.25
Output price / 1M tokens$0.34$2.50
Context window262K tokens2M tokens
Max output tokens16K1.8M
API providers listed111
Weight accessOpen weightsAPI only
Input modalitiesImage, Text, VideoText, Image, File
First listed2 April 202631 March 2026
PublisherGooglexAI

Evidence: 3 public benchmark observations across 3 boards · 2 public benchmark observations across 2 boards. Prices are the lowest listed API offer per million tokens observed on the OpenRouter catalogue.

Benchmark scores: Gemma 4 31B vs Grok 4.20 Multi-Agent

Public benchmark boards where Gemma 4 31B or Grok 4.20 Multi-Agent has a published result
BoardGemma 4 31BGrok 4.20 Multi-AgentLeads
Arena codingArena (LMArena)14991483–151415081502–1514Beta · 0309Grok 4.20 Multi-Agent
AA τ²-Bench TelecomArtificial Analysis65.5%tau2:telecom:dual-control:pass-at-1:3-repeats:source-model="Gemma 4 31B (Non-reasoning)":reasoning=false—Only one result
AA Humanity's Last ExamArtificial Analysis11.8%hle:may-2025:text-only-2158:no-tools:pass-at-1:source-model="Gemma 4 31B (Non-reasoning)":reasoning=false—Only one result
WildClawBench OpenClawWildClawBench37.6—Only one result

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.

Gemma 4 31B vs Grok 4.20 Multi-Agent: common questions

Is Gemma 4 31B better than Grok 4.20 Multi-Agent?

Grok 4.20 Multi-Agent ranks higher on the ModelCap Index as of 22 September 2026: #18 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.

Is Gemma 4 31B cheaper than Grok 4.20 Multi-Agent?

Gemma 4 31B is cheaper on output tokens: $0.34/1M against $2.50/1M. Input tokens are $0.09/1M for Gemma 4 31B and $1.25/1M for Grok 4.20 Multi-Agent. Prices are the lowest listed API offer ModelCap observed, in USD per million tokens. For 1,000 requests with 2,000 input and 500 output tokens each (2M input + 0.5M output), the listed-rate estimate is $0.35 for Gemma 4 31B versus $3.75 for Grok 4.20 Multi-Agent. Gemma 4 31B costs 90.7% less in this scenario. This excludes caching, batch discounts, prompt-length tiers, tool charges and retries; verify the selected endpoint before budgeting.

Which has the bigger context window, Gemma 4 31B or Grok 4.20 Multi-Agent?

Grok 4.20 Multi-Agent has the larger context window: 2M tokens against 262K.

Which is better for coding, Gemma 4 31B or Grok 4.20 Multi-Agent?

Arena coding: Gemma 4 31B 1499, Grok 4.20 Multi-Agent 1508 — Grok 4.20 Multi-Agent leads.

Are Gemma 4 31B and Grok 4.20 Multi-Agent open-weight models?

Gemma 4 31B: Open weights. 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.

Where can I run Gemma 4 31B and Grok 4.20 Multi-Agent?

ModelCap currently lists 11 API providers for Gemma 4 31B 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.

How current is this Gemma 4 31B vs Grok 4.20 Multi-Agent comparison?

Every figure comes from the sealed ModelCap dataset published 22 September 2026; the page re-renders within a minute of each data refresh, and the ModelCap Index positions are the same ones shown on the live rankings.

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