OpenAI: gpt-oss-20b

apache-2.020B

gpt-oss-20b is an open-weight 21B parameter model released by OpenAI under the Apache 2.0 license.

Intelligence
Reasoning
Speed
Context
131K
Max output
33K
Input price
$0.02/1M tokens
Output price
$0.09/1M tokens

Capabilities

Reasoning & Interaction
Reasoning
Tool Calling
Output Control
Structured Output
JSON Mode
Infrastructure
Streaming
Batch Processing

Details

Model IDopenai/gpt-oss-20b
Provider OpenRouter
Creator OpenAI
Familygpt-oss
Licenseapache-2.0
Statusactive
Typechat
Input modalitiestext
Output modalitiestext
Open weightYes
Parameters20B
Architecture—
Context window131K tokens
Max input—
Max output33K tokens
Reasoning tokensYes
Knowledge cutoff
Release date
Sourceofficial

Tools

Function Callingfunction_calling
Call external functions and APIs

Pricing

Input
$0.02
Output
$0.09
Cache write
—
Cache read
$0.01
Batch in
—
Batch out
—

Family Comparison: gpt-oss

ModelContextMax outPricing
OpenAI: gpt-oss-120b (free)131K131K—
OpenAI: gpt-oss-20b (free)131K33K—
OpenAI: gpt-oss-20b131K33K$0.02$0.09
OpenAI: gpt-oss-20b (batch)131K118K$0.02$0.11
OpenAI: gpt-oss-120b (batch)131K118K$0.03$0.14
OpenAI: gpt-oss-safeguard-20b131K66K$0.08$0.3
OpenAI: gpt-oss-120b131K66K$0.15$0.6

API

GET/v1/models/openrouter/openai/gpt-oss-20b

OpenAI: gpt-oss-20b

openai/gpt-oss-20b

gpt-oss-20b is an open-weight 21B parameter model released by OpenAI under the Apache 2.0 license.

Changes · 15 entries
openai/gpt-oss-20bupdateca7a400Nov 2, 2026, 03:02 AM
max_output_tokens131072→32768
pricinginput$0.03→$0.018output$0.14→$0.09cached input$0.015→$0.009
openai/gpt-oss-20bupdate1a66bb0Sep 29, 2026, 06:40 AM
pricingcached input$0.03→$0.009
openai/gpt-oss-20bupdate28ec4f5Sep 23, 2026, 06:40 AM
max_output_tokens117964→32768
pricinginput$0.03→$0.018output$0.13→$0.09
openai/gpt-oss-20bupdatee3d7dedAug 31, 2026, 04:13 AM
max_output_tokens131072→117964
openai/gpt-oss-20bupdate86db01cAug 2, 2026, 08:20 AM
pricingoutput$0.14→$0.13
openai/gpt-oss-20bupdatec67ed84Jul 31, 2026, 10:28 AM
pricingoutput$0.13→$0.14
openai/gpt-oss-20bupdate97fe10eJul 25, 2026, 09:55 AM
pricinginput$0.029→$0.03output$0.14→$0.13
openai/gpt-oss-20bupdatebf78dcfJul 25, 2026, 05:49 AM
pricinginput$0.03→$0.029output$0.13→$0.14
openai/gpt-oss-20bupdate20c73acJul 17, 2026, 02:34 AM
pricinginput$0.029→$0.03output$0.14→$0.13cached input$0.015→$0.03
openai/gpt-oss-20bupdated657a45Jun 3, 2026, 03:19 AM
pricinginput$0.03→$0.029
openai/gpt-oss-20bupdate14e5cfdApr 13, 2026, 02:40 AM
pricingoutput$0.11→$0.14
openai/gpt-oss-20bupdate1cd659eMar 24, 2026, 04:19 AM
capabilitiesjson modeyes
openai/gpt-oss-20bupdate2b100acMar 23, 2026, 05:30 AM
model_typechat
parameters20
release_date2025-08-05
taglinegpt-oss-20b is an open-weight 21B parameter model release...
tools["function_calling"]
openai/gpt-oss-20bupdateb50649fMar 21, 2026, 11:58 PM
pricingoutput$0.14→$0.11cached input$0.015
max_output_tokens131072
openai/gpt-oss-20bcreate7f5c66fMar 21, 2026, 05:16 AM