GPT-OSS 120B is an open-weight Mixture-of-Experts language model released by OpenAI in August 2025 under the Apache 2.0 license. It has 116.8B total parameters with 5.1B active per token across 36 layers, allowing it to run on a single 80GB GPU. The model reaches near-parity with OpenAI o4-mini on core reasoning benchmarks and outperforms similarly sized open models on reasoning tasks. It offers strong tool use with function calling and structured outputs, making it well suited to agentic and complex reasoning workflows. Its MoE design selects the top 4 of 128 experts per token and uses grouped query attention with rotary positional embeddings over a 128k context window.
Call GPT OSS 120B on Opper with the OpenAI SDK. Sign up without a credit card. Get started
GPT OSS 120B runs on 16 different routes through the Opper gateway. Compare residency, zero data retention and training posture at a glance, with full data-handling detail per route below.
| Provider | Region | Zero data retention | Training | Input | Output | Cache read |
|---|---|---|---|---|---|---|
| EU | No | $0.15 | $0.60 | Input price | ||
| Multi | No | $0.10 | $0.50 | Input price | ||
| US | No | $0.35 | $0.75 | Input price | ||
| US | No | $0.06 | $0.39 | Input price | ||
| EU | No | $0.23 | $0.91 | Input price | ||
| Multi | No | $0.15 | $0.60 | $0.01 | ||
| EU/EEA | No | $0.04 | $0.18 | Input price | ||
| US | No | $0.04 | $0.18 | Input price | ||
| EU | No | $0.23 | $0.80 | Input price | ||
| US | No | $0.15 | $0.60 | $0.07 | ||
| EU | No | $0.25 | $0.67 | Input price | ||
| Multi | No | $0.15 | $0.60 | Input price | ||
| US | No | $0.05 | $0.25 | Input price | ||
| EU | No | $1.14 | $4.79 | Input price | ||
| EU | No | $0.17 | $0.68 | Input price | ||
| Multi | No | $0.36 | $1.17 | Input price |
GPT OSS 120B runs on 6 independently monitored routes through the Opper gateway. A direct integration leaves you on one of them, the gateway serves whichever is healthy.
Measured over the last 30 days from each provider's official status feed via StatusGator. Refreshed hourly. 9 further routes for this model are not on the board yet and are not counted above. See uptime for every provider Opper monitors.
Each route hosting GPT OSS 120B has its own privacy posture, residency, and GDPR terms. Postures are maintained by Opper with a last-verification timestamp.
Zero data retention: nothing is logged, held for abuse monitoring or used for training. No training on customer data. EU; DPA available.
Zero data retention with abuse monitoring: prompts and outputs are kept for up to 180 days for abuse monitoring only, and are not used for training. No training on customer data. GLOBAL; SCCs; DPA available.
Zero data retention: nothing is logged, held for abuse monitoring or used for training. No training on customer data. US; SCCs; DPA available.
Zero data retention with abuse monitoring: nothing is logged or used for training; content flagged by abuse monitoring is held for review. No training on customer data. US; dpf sccs; DPA available.
Zero data retention: nothing is logged, held for abuse monitoring or used for training. No training on customer data. EU; DPA available.
Zero data retention: nothing is logged, held for abuse monitoring or used for training. No training on customer data. GLOBAL; SCCs; DPA available.
Zero data retention: nothing is logged, held for abuse monitoring or used for training. No training on customer data. EEA; SCCs; DPA available.
Zero data retention: nothing is logged, held for abuse monitoring or used for training. No training on customer data. US; SCCs; DPA available.
Zero data retention: nothing is logged, held for abuse monitoring or used for training. No training on customer data. EU; DPA available.
Zero data retention: nothing is logged, held for abuse monitoring or used for training. No training on customer data. US; SCCs; DPA available.
Zero data retention: nothing is logged, held for abuse monitoring or used for training. No training on customer data. EU; DPA available.
Content is retained: provider logging. No training on customer data. GLOBAL; SCCs; DPA available.
Zero data retention: nothing is logged, held for abuse monitoring or used for training. No training on customer data. US; SCCs; DPA available.
Zero data retention: nothing is logged, held for abuse monitoring or used for training. No training on customer data. EU; DPA available.
Zero data retention with abuse monitoring: prompts and outputs are kept for up to 14 days for abuse monitoring only, and are not used for training. No training on customer data. EU; DPA available.
Zero data retention: nothing is logged, held for abuse monitoring or used for training. No training on customer data. GLOBAL; unknown; DPA available.
Independent benchmark scores — composite indices for reasoning, coding, and math, plus individual eval scores where available.
Call GPT OSS 120B through the Opper gateway with one API key. Opper is drop-in compatible with the OpenAI, Anthropic and Google AI SDKs.
GPT OSS 120B is a premium model on Opper. Sign up needs no credit card: you get an API key straight away and the free models work in the playground and the API. Add a card to use premium models, pay-as-you-go with no minimum.
Copy this and paste it into a coding agent like Claude Code, Cursor or Codex and it'll wire up Opper for you.
import OpenAI from "openai";const client = new OpenAI({apiKey: process.env.OPPER_API_KEY,baseURL: "https://api.opper.ai/v3/compat",});const completion = await client.chat.completions.create({model: "gpt-oss-120b",messages: [{ role: "user", content: "Hello" }],});console.log(completion.choices[0].message.content);
Side-by-side on privacy, EU hosting, pricing, and benchmarks.
