Choose IBM: Granite 4.2 8B if…
- you generate long outputs in one go — up to 118K tokens (about 88,500 words) per response
- you want the newer model — released 2026-08-31, 13 months after the other
IBM: Granite 4.2 8B vs OpenAI: gpt-oss-20b
Neither wins outright: IBM: Granite 4.2 8B is the pick when you generate long outputs in one go, OpenAI: gpt-oss-20b when cost matters at scale.
Key numbers
| Spec | IBM: Granite 4.2 8B | OpenAI: gpt-oss-20b |
|---|---|---|
| Provider | Ibm Granite | OpenAI |
| Input price (per 1M tokens) | $0.06 | $0.02 |
| Output price (per 1M tokens) | $0.25 | $0.09 |
| Blended price (3:1 input/output) | $0.11 | $0.04 |
| Cheaper than … of all models we track | 79% | 88% |
| Context window | 131K tokens (~197 pages) | 131K tokens (~197 pages) |
| Larger context than … of all models | 23% | 23% |
| Max output per response | 118K tokens (~88,500 words) | 33K tokens (~24,600 words) |
| Input types | text | text |
| Output types | text | text |
| Free variant | No | Yes |
| Listed since | 2026-08-31 | 2025-08-05 |
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What it costs for real workloads
Monthly cost at list price for five common workloads. Token counts per unit are stated so you can scale them to your own traffic. A workload that does not fit a model's context window is marked rather than priced.
| Workload (per month) | IBM: Granite 4.2 8B | OpenAI: gpt-oss-20b | Difference |
|---|---|---|---|
| Customer-support chatbot 50,000 conversations — each a 6-turn conversation (1,500 in / 400 out tokens) | $9.50 | $3.15 | OpenAI: gpt-oss-20b saves $6.35 |
| RAG search over documents 20,000 questions — each a question answered from ~8 retrieved passages (6,000 in / 500 out tokens) | $9.70 | $3.06 | OpenAI: gpt-oss-20b saves $6.64 |
| Coding / tool-using agent 2,000 tasks — each a multi-step task with tool calls and file context (60,000 in / 6,000 out tokens) | $10.20 | $3.24 | OpenAI: gpt-oss-20b saves $6.96 |
| Batch summarisation 10,000 documents — each a 6,000-word report summarised to a page (8,000 in / 600 out tokens) | $6.30 | $1.98 | OpenAI: gpt-oss-20b saves $4.32 |
| Long-document analysis 500 documents — each a 150-page contract or codebase read in one pass (100,000 in / 2,000 out tokens) | $3.25 | $0.99 | OpenAI: gpt-oss-20b saves $2.26 |
Capabilities side by side
| Capability | IBM: Granite 4.2 8B | OpenAI: gpt-oss-20b | What it lets you do |
|---|---|---|---|
| Tool / function calling | ✓ Yes | ✓ Yes | call your APIs and run agent loops |
| Structured output (JSON schema) | ✓ Yes | ✓ Yes | return JSON that validates against your schema |
| Reasoning / thinking mode | ✓ Yes | ✓ Yes | spend extra tokens thinking before answering hard problems |
| Image input | — | — | read screenshots, charts and scanned pages |
| Audio input | — | — | take speech or audio directly |
| File / PDF input | — | — | accept documents without your own parsing step |
| Image output | — | — | generate images, not just text |
| Built-in web search | — | — | answer from live web results |
| Seed (reproducible sampling) | ✓ Yes | ✓ Yes | repeat a generation for tests and evals |
| Log-probabilities | ✓ Yes | ✓ Yes | read token confidence for classification and scoring |
From each model's published parameters and input/output types. “—” means not advertised, not proven absent.
Price history
- IBM: Granite 4.2 8B: input price cut 40% ($0.10 → $0.06/1M), output price raised 40% ($0.15 → $0.25/1M) on 2026-09-22 (3 price changes since 2026-09-01).
- OpenAI: gpt-oss-20b: input price cut 40% ($0.03 → $0.02/1M), output price cut 31% ($0.13 → $0.09/1M) on 2026-09-23 (3 price changes since 2026-03-10).
| Date | Model | Input / 1M | Output / 1M |
|---|---|---|---|
| 2026-09-23 | OpenAI: gpt-oss-20b | $0.02 | $0.09 |
| 2026-09-22 | IBM: Granite 4.2 8B | $0.06 | $0.25 |
| 2026-09-21 | IBM: Granite 4.2 8B | $0.10 | $0.15 |
| 2026-09-09 | IBM: Granite 4.2 8B | $0.06 | $0.25 |
| 2026-08-06 | OpenAI: gpt-oss-20b | $0.03 | $0.13 |
| 2026-03-31 | OpenAI: gpt-oss-20b | $0.03 | $0.11 |
Which should you choose?
Choose OpenAI: gpt-oss-20b if…
- cost matters at scale — it is 67% cheaper on a typical 3:1 input/output mix ($3.15 vs $9.50 a month for 50,000 support chats)
- you want to prototype at zero cost — a free variant is listed
Frequently asked questions
Is IBM: Granite 4.2 8B better than OpenAI: gpt-oss-20b?
Neither wins outright: IBM: Granite 4.2 8B is the pick when you generate long outputs in one go, OpenAI: gpt-oss-20b when cost matters at scale. In short: IBM: Granite 4.2 8B when you generate long outputs in one go, you want the newer model; OpenAI: gpt-oss-20b when cost matters at scale, you want to prototype at zero cost.
Which is cheaper, IBM: Granite 4.2 8B or OpenAI: gpt-oss-20b?
OpenAI: gpt-oss-20b is cheaper: $0.04 vs $0.11 per 1M tokens at a typical 3:1 input/output mix, 67% less. For 50,000 support conversations a month that is $3.15 against $9.50.
How much do IBM: Granite 4.2 8B and OpenAI: gpt-oss-20b cost per million tokens?
IBM: Granite 4.2 8B costs $0.06 per 1M input tokens and $0.25 per 1M output tokens; OpenAI: gpt-oss-20b costs $0.02 input and $0.09 output. Output tokens are billed separately, so long answers shift the gap.
Which has the bigger context window, IBM: Granite 4.2 8B or OpenAI: gpt-oss-20b?
Both take 131K tokens per request — roughly 197 pages of text.
Do IBM: Granite 4.2 8B and OpenAI: gpt-oss-20b support function calling and JSON output?
Tool calling — IBM: Granite 4.2 8B: yes, OpenAI: gpt-oss-20b: yes. JSON-schema structured output — IBM: Granite 4.2 8B: yes, OpenAI: gpt-oss-20b: yes.
Can IBM: Granite 4.2 8B or OpenAI: gpt-oss-20b read images?
Neither accepts image input — both are text-in models.
Is IBM: Granite 4.2 8B or OpenAI: gpt-oss-20b free to use?
OpenAI: gpt-oss-20b has a free variant (openai/gpt-oss-20b:free). Free variants usually carry tighter rate limits.
What is the maximum output length of IBM: Granite 4.2 8B and OpenAI: gpt-oss-20b?
IBM: Granite 4.2 8B can write up to 118K tokens (about 88,500 words) per response; OpenAI: gpt-oss-20b up to 33K (about 24,600 words).
When were IBM: Granite 4.2 8B and OpenAI: gpt-oss-20b released?
IBM: Granite 4.2 8B was listed on 2026-08-31; OpenAI: gpt-oss-20b on 2025-08-05.
Has the price of IBM: Granite 4.2 8B or OpenAI: gpt-oss-20b changed?
IBM: Granite 4.2 8B: input price cut 40% ($0.10 → $0.06/1M), output price raised 40% ($0.15 → $0.25/1M) on 2026-09-22 (3 price changes since 2026-09-01). OpenAI: gpt-oss-20b: input price cut 40% ($0.03 → $0.02/1M), output price cut 31% ($0.13 → $0.09/1M) on 2026-09-23 (3 price changes since 2026-03-10).
About the two models
IBM: Granite 4.2 8B
Granite 4.2 8B is a dense reasoning model from IBM. It is suited for mathematics, code generation, multilingual dialogue, and agentic workflows that need multi-step reasoning. It supports full, low-effort,...
Full IBM: Granite 4.2 8B specs →OpenAI: gpt-oss-20b
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...
Full OpenAI: gpt-oss-20b specs →