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Model comparison

Gemma 4 E4B IT vs GPT OSS 20B (free)

Gemma 4 E4B IT (Google) and GPT OSS 20B (free) (OpenAI) side by side: what each costs per million tokens through Rapid Router, how much context each takes, what each supports, and where independent benchmarks place them. Same API, same key; switching is a one-string change.

Gemma 4 E4B ITGPT OSS 20B (free)
Input price per 1M$0.020$0.030
Output price per 1M$0.100$0.140
Context window131K tokens131K tokens
Max output8K tokens16K tokens
Input typestext, image, audiotext
Capabilitiestools, JSON, vision, audio, reasoningtools, reasoning
AuthorGoogleOpenAI

What a month costs on each

WorkloadGemma 4 E4B ITGPT OSS 20B (free)
Chatbot month (15M in, 4M out)$0.700$1.01
RAG month (40M in, 3M out)$1.10$1.62
Coding month (60M in, 10M out)$2.20$3.20

On a typical 75/25 input-output mix, Gemma 4 E4B IT costs less (about 30% less than GPT OSS 20B (free)). Gemma 4 E4B IT takes the longer prompt at 131K tokens. Try your own numbers in the cost calculator.

Call either one

curl https://rapidrouter.ai/api/v1/chat/completions \
  -H "Authorization: Bearer $RAPIDROUTER_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model": "google/gemma-4-e4b-it", "messages": [{"role": "user", "content": "Hello"}]}'

# the other one: change the model string
  -d '{"model": "openai/gpt-oss-20b:free", ...}'

Common questions

Which is cheaper, Gemma 4 E4B IT or GPT OSS 20B (free)?

Gemma 4 E4B IT is cheaper on a typical mix of 75% input and 25% output tokens, by about 30%. Through Rapid Router both are billed at the provider list price per million tokens.

Which has the larger context window?

Gemma 4 E4B IT, at 131K tokens. GPT OSS 20B (free) offers 131K tokens.

Can I switch between Gemma 4 E4B IT and GPT OSS 20B (free) without changing code?

Yes. Both are callable at https://rapidrouter.ai/api/v1 with the same OpenAI-compatible request; only the model string changes (google/gemma-4-e4b-it or openai/gpt-oss-20b:free).

How do I pay for Gemma 4 E4B IT or GPT OSS 20B (free)?

Top up a Rapid Router balance by card in US dollars, and both models debit that balance per request.

More Gemini models: Google API pricing · More GPT: OpenAI API pricing