API cost decision in 10 seconds

gpt-oss-120b (free) vs gpt-oss-20b (free)

The standard workload cost is tied; choose by context window, provider fit, latency, or model quality.

Page updated: 2026-05-26T15:08:08Z Data confirmed: 2026-05-26T19:08:13Z Prices normalized to USD per 1M tokens Sample workload: 1M input + 500K output

Budget verdict

The standard workload cost is tied; choose by context window, provider fit, latency, or model quality.

Both models are estimated at $0 for the standard 1M input plus 500K output workload.

Cost-first pickTie

Context-first pickBoth models

Sample savings$00%

10x traffic gap$0

Context-window winner: Both models. Cost does not separate this pair on the standard workload, so the next decision point is context window and model behavior.

Cost sensitivity

Workload Sensitivity

Same prices, different token mixes.

The two models stay tied across the input-heavy, balanced, and output-heavy sample workloads.

Workload shape	Token mix	Better pick	gpt-oss-120b (free)	gpt-oss-20b (free)
Input-heavy / RAG	5M input + 500K output	Tie	$0	$0
Balanced workload	1M input + 1M output	Tie	$0	$0
Output-heavy chatbot	1M input + 5M output	Tie	$0	$0

Cheaper input Tie $0 vs $0 / 1M

Both models report the same input price at $0 per 1M tokens.

Cheaper output Tie $0 vs $0 / 1M

Both models report the same output price at $0 per 1M tokens.

Larger context Tie 131.07K vs 131.07K

Both models report the same context window at 131.07K tokens.

Sample workload Tie $0 vs $0

Both models have the same estimated cost for the standard 1M input plus 500K output workload: $0.

Estimate your workload cost

Your Workload Cost

Prices are normalized to USD per 1M tokens.

Monthly input tokens Monthly output tokens

gpt-oss-120b (free) Calculating… Estimated API cost

gpt-oss-20b (free) 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

both models tie on input price; both models tie on output price; both models report the same context window. For the 1M input plus 500K output sample, the standard workload cost is tied.

For a 1M input token plus 500K output token workload, the estimated API cost is $0 for gpt-oss-120b (free) and $0 for gpt-oss-20b (free).

Best Fit

Choose gpt-oss-120b (free) when its provider, model quality, latency, or availability is more important than the numeric price/context winner.

Choose gpt-oss-20b (free) when its provider, model quality, latency, or availability is more important than the numeric price/context winner.

Decision Notes

Both models are estimated at $0 for the standard 1M input plus 500K output workload.
Both models have the same estimated cost for the standard 1M input plus 500K output workload: $0.
Both models report the same input price at $0 per 1M tokens.
Both models report the same output price at $0 per 1M tokens.
Both models report the same context window at 131.07K tokens.

Head-to-Head Specs

Feature	gpt-oss-120b (free) (OpenAI)	gpt-oss-20b (free) (OpenAI)
Input Price prompt tokens per 1M	$0	$0
Completion Price per 1M tokens	$0	$0
Sample Workload Cost 1M input + 500K output	$0	$0
Context Window	131.07K	131.07K
Release Date	2025-08-05	2025-08-05
Popularity	#26	#72

Use-Case Decision Matrix

Use case	Better pick	Why
Budget-constrained production	Tie	Both models are estimated at $0 for the standard 1M input plus 500K output workload.
High-volume input processing	Tie	Lower prompt-token price matters most when prompts, retrieved passages, or documents dominate the bill.
Long responses and chatbots	Tie	Lower output-token price matters most when assistants generate many completion tokens.
RAG or long-document work	Tie	A larger context window leaves more room for retrieved passages, conversation history, or source files.

Related Alternatives

Same-provider lower-cost swaps

No lower-cost same-provider swap is currently tracked for this pair.

Larger context near this budget

Owl Alpha offers 1.05M context with $0 sample workload cost.
DeepSeek V4 Flash (free) offers 1.05M context with $0 sample workload cost.
Lyria 3 Clip Preview offers 1.05M context with $0 sample workload cost.
Lyria 3 Pro Preview offers 1.05M context with $0 sample workload cost.

Popular competitors

DeepSeek V4 Flash · DeepSeek · #1
Hy3 preview · Tencent · #2
Claude Opus 4.7 · Anthropic · #3
Claude Sonnet 4.6 · Anthropic · #4

Cheaper alternatives

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Open cheapest models

Larger context alternatives

Find models with larger context windows for RAG, long documents, and codebase review.

Open largest context models

Provider catalogs

Compare models within provider hubs before choosing a final API vendor.

Open provider hubs

OpenAI catalog

Review all tracked OpenAI models before deciding whether this matchup is the right shortlist.

Open OpenAI models

gpt-oss-120b (free)

gpt-oss-120b is an open-weight, 117B-parameter Mixture-of-Experts (MoE) language model from OpenAI designed for high-reasoning, agentic, and general-purpose production use cases. It activates 5.1B parameters per forward pass and is optimized...

gpt-oss-20b (free)

gpt-oss-20b is an open-weight 21B parameter model released by OpenAI under the Apache 2.0 license. It uses a Mixture-of-Experts (MoE) architecture with 3.6B active parameters per forward pass, optimized for...