Gemini 4 or Gemma 4? It Depends. A developer benchmarked seven Google models — Gemma 4 26B and 31B, Gemini 3.5 Flash-Lite, 3.8 Flash, and Gemini 4 Hydrogen, Carbon and Argon — through the same Gemini API endpoint with identical prompts and settings. On 1,319 GSM8K math problems Argon led at 0.9841 accuracy, while Gemma 4 31B tied Argon at 0.9675 on 400 BFCL function calls and ran free versus $0.92–$5.02 for the Gemini runs. The results show per-token price alone misleads: Hydrogen, the cheapest Gemini 4 model at $7.50 per million output tokens, cost the most per run ($5.02) because reasoning cannot be disabled on Gemini 4 and thinking accounted for 55% of its GSM8K bill. This article provides a step by step guide to comparing the new Gemini 4 models with Gemma 4 on equal terms. Seven models, Gemma 4 26B and 31B, Gemini 3.5 Flash-Lite and 3.8 Flash, and Gemini 4 Hydrogen, Carbon and Argon, run through the same Gemini API endpoint with the same questions, settings and scoring, started at the same moment. https://github.com/xbill9/gemma4-dev/tree/main/gemini-api-google-hydrogen4 https://github.com/xbill9/gemma4-dev/tree/main/gemini-api-google-hydrogen4 The scores: on 1,319 GSM8K math problems Argon scored 0.9841, Hydrogen and Carbon 0.9803, 3.8 Flash 0.9788, Gemma 4 26B 0.9742, Gemma 4 31B 0.9735 and 3.5 Flash-Lite 0.9629. On 400 BFCL function calls Argon and Gemma 4 31B tied at 0.9675. Gemma 4 ran free; the Gemini runs cost $0.92 to $5.02. Hydrogen answered fastest of the Gemini 4 models, 2.84 s per GSM8K problem against 7.63 s for Argon. The surprise is in the cost, and it takes the whole picture to see it. Hydrogen is the cheapest Gemini 4 model per token, $7.50 per million output tokens against $10 for Carbon and Argon, and it cost the most per run, $5.02 against $3.46 for Argon. Its thinking eats the token budget: Google's docs say reasoning cannot be turned off on Gemini 4 models, it ran on all 1,319 GSM8K problems at the lowest setting, and it was 55% of the GSM8K bill. Price per token, tokens per answer and thinking per answer together set what a model costs. Gemini 4 Hydrogen, Carbon and Argon are on the Gemini API next to the 3.x Flash models and Gemma 4. Google's pricing page, saved on 2026-11-14 paid tier, USD per million tokens; output includes thinking tokens : | Model | Input | Output | Free tier | |---|---|---|---| | gemma-4-31b-it , gemma-4-26b-a4b-it | free tier only | free tier only | yes | | gemini-3.5-flash-lite | $0.30 | $2.50 | yes | | gemini-3.8-flash | $0.75 | $3.75 | yes | | gemini-4-hydrogen | $1.50 | $7.50 | yes | | gemini-4-carbon | $2.00 | $10.00 | no | | gemini-4-argon | $2.00 | $10.00 | no | Carbon and Argon go to $4 / $20 on 2026-12-01, and 3.8 Flash to $1.50 / $7.50 on 2027-01-01. Every model got: /v1beta/openai/chat/completions on the Gemini API Step 2 shows that setting for each model, and the two models that keep thinking at it. ~/gemini.key gemma4-dev The Gemini API answers OpenAI chat requests with the key as a Bearer token. Gemma 4 and Gemini take the same request body; only model changes: curl -sS https://generativelanguage.googleapis.com/v1beta/openai/chat/completions \ -H "Authorization: Bearer $ cat ~/gemini.key " -H 'Content-Type: application/json' \ -d '{"model":"gemma-4-31b-it","temperature":0,"max tokens":2048,"reasoning effort":"minimal", "messages": {"role":"user","content":"Janet has 16 eggs, eats 3, bakes with 4, sells the rest at $2. How much does she make? End with Answer: