API cost decision in 10 seconds

Gemma 4 31B vs Grok 4.20

Pick Gemma 4 31B for lower cost; pick Grok 4.20 only if the larger context window matters more.

Pricing data updated: 2026-05-26T11:08:00Z Prices normalized to USD per 1M tokens Sample workload: 1M input + 500K output

Budget verdict

Pick Gemma 4 31B for lower cost; pick Grok 4.20 only if the larger context window matters more.

On the standard 1M input plus 500K output workload, Gemma 4 31B is estimated at $0.3 vs $2.5 for Grok 4.20, saving $2.19 (87.8% lower).

Cost-first pickGemma 4 31B

Context-first pickGrok 4.20

Sample savings$2.1987.8%

10x traffic gap$21.95

Grok 4.20 has more context, but Gemma 4 31B saves $2.19 on the standard workload. At 10x that traffic, the same price gap is about $21.95. Use the calculator below to replace the sample workload with your own token volume.

Cost sensitivity

Workload Sensitivity

Same prices, different token mixes.

Gemma 4 31B stays cheaper across input-heavy, balanced, and output-heavy sample workloads.

Workload shape	Token mix	Better pick	Gemma 4 31B	Grok 4.20
Input-heavy / RAG	5M input + 500K output	Gemma 4 31B	$0.78	$7.5
Balanced workload	1M input + 1M output	Gemma 4 31B	$0.49	$3.75
Output-heavy chatbot	1M input + 5M output	Gemma 4 31B	$1.97	$13.75

Cheaper input Gemma 4 31B $0.12 vs $1.25 / 1M

Gemma 4 31B is $1.13 cheaper per 1M input tokens (90.4% lower; 10.4x difference).

Cheaper output Gemma 4 31B $0.37 vs $2.5 / 1M

Gemma 4 31B is $2.13 cheaper per 1M output tokens (85.2% lower; 6.76x difference).

Larger context Grok 4.20 262.14K vs 2M

Grok 4.20 has 1.74M more context (7.63x larger).

Sample workload Gemma 4 31B $0.3 vs $2.5

Gemma 4 31B is $2.19 cheaper on the standard workload (87.8% lower).

Estimate your workload cost

Your Workload Cost

Prices are normalized to USD per 1M tokens.

Monthly input tokens Monthly output tokens

Gemma 4 31B Calculating… Estimated API cost

Grok 4.20 Calculating… Estimated API cost

Cheaper for this workload Calculating… Difference: calculating…

This estimate uses normalized public API pricing per 1M tokens. It is a planning aid, not a billing quote. Verify provider pricing, limits, and terms before production use.

Quick Decision

Verdict

Gemma 4 31B has the lower input price; Gemma 4 31B has the lower output price; Grok 4.20 offers the larger context window. For the 1M input plus 500K output sample, Gemma 4 31B is cheaper for the standard workload.

For a 1M input token plus 500K output token workload, the estimated API cost is $0.3 for Gemma 4 31B and $2.5 for Grok 4.20.

Best Fit

Choose Gemma 4 31B when you care most about lower input-token price, and lower output-token price.

Choose Grok 4.20 when you care most about larger context window.

Decision Notes

On the standard 1M input plus 500K output workload, Gemma 4 31B is estimated at $0.3 vs $2.5 for Grok 4.20, saving $2.19 (87.8% lower).
Gemma 4 31B is $2.19 cheaper on the standard workload (87.8% lower).
Gemma 4 31B is $1.13 cheaper per 1M input tokens (90.4% lower; 10.4x difference).
Gemma 4 31B is $2.13 cheaper per 1M output tokens (85.2% lower; 6.76x difference).
Grok 4.20 has 1.74M more context (7.63x larger).

Head-to-Head Specs

Feature	Gemma 4 31B (Google)	Grok 4.20 (xAI)
Input Price prompt tokens per 1M	$0.12	$1.25
Completion Price per 1M tokens	$0.37	$2.5
Sample Workload Cost 1M input + 500K output	$0.3	$2.5
Context Window	262.14K	2M
Release Date	2026-04-02	2026-03-31

Use-Case Decision Matrix

Use case	Better pick	Why
Budget-constrained production	Gemma 4 31B	On the standard 1M input plus 500K output workload, Gemma 4 31B is estimated at $0.3 vs $2.5 for Grok 4.20, saving $2.19 (87.8% lower).
High-volume input processing	Gemma 4 31B	Lower prompt-token price matters most when prompts, retrieved passages, or documents dominate the bill.
Long responses and chatbots	Gemma 4 31B	Lower output-token price matters most when assistants generate many completion tokens.
RAG or long-document work	Grok 4.20	A larger context window leaves more room for retrieved passages, conversation history, or source files.

Related Alternatives

Same-provider lower-cost swaps

Gemma 4 26B A4B (free) can replace Gemma 4 31B when lower sample workload cost matters most: $0.
Gemma 4 31B (free) can replace Gemma 4 31B when lower sample workload cost matters most: $0.
Lyria 3 Pro Preview can replace Gemma 4 31B when lower sample workload cost matters most: $0.
Lyria 3 Clip Preview can replace Gemma 4 31B when lower sample workload cost matters most: $0.

Larger context near this budget

Llama 4 Scout offers 10M context with $0.23 sample workload cost.

Popular competitors

No popular competitor is currently available.

Cheaper alternatives

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Larger context alternatives

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Provider catalogs

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Google catalog

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xAI catalog

Check other xAI models with comparable pricing, context, or release timing.

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Gemma 4 31B

Gemma 4 31B Instruct is Google DeepMind's 30.7B dense multimodal model supporting text and image input with text output. Features a 256K token context window, configurable thinking/reasoning mode, native function...

Grok 4.20

Grok 4.20 is a reasoning model from xAI with industry-leading speed and agentic tool calling capabilities. It combines the lowest hallucination rate on the market with strict prompt adherance, delivering...