Bring your own key: OpenAI's API rates, no markup. Keys and chats stay in your browser. Run OpenAI in parallel with other models, then compare and merge the answers.
GPT-5.6 Sol
NEWFlagship next-generation model. Strongest yet for agentic coding, science, and cybersecurity, with the most robust safety stack to date. 1M token context.
1.1M
$5
$30
Jun 2026
GPT-5.6 Terra
NEWBalanced model for efficient, high-volume everyday work. Competitive with GPT-5.5 while being 2x cheaper. 1M token context.
1.1M
$2.5
$15
Jun 2026
GPT-5.6 Luna
NEWFastest, most affordable GPT-5.6 model for high-volume work. Strong capability at the lowest cost in the family. 1M token context.
1.1M
$1
$6
Jun 2026
GPT-5.5
New baseline for complex production workflows. Stronger task execution, more precise tool use, more efficient reasoning with fewer tokens. 1M token context.
1.1M
$5
$30
Apr 2026
GPT-5.5 Pro
Most capable model for complex tasks. Uses more compute for smarter, more precise responses on the hardest problems.
1.1M
$30
$180
Apr 2026
GPT-5.4 Mini
Strongest mini model for coding, computer use, and subagents. GPT-5.4-class intelligence at lower cost and latency.
400K
$0.75
$4.5
Mar 2026
GPT-5.4 Nano
Cheapest GPT-5.4-class model for simple high-volume tasks like classification and data extraction.
400K
$0.2
$1.25
Mar 2026
GPT-5.4
Most capable and efficient frontier model for professional work. Native computer use, improved reasoning, coding, and agentic workflows with 1M token context.
1.1M
$2.5
$15
Mar 2026
GPT-5.4 Pro
Most capable model for complex tasks. Uses more compute for smarter, more precise responses on difficult problems.
1.1M
$30
$180
Mar 2026
GPT-5.3 Instant
deprecatedGPT-5.3 Instant model, previously powering ChatGPT. Replaced by GPT-5.5 Instant.
128K
$1.75
$14
Mar 2026
GPT Audio 1.5
Best voice model for audio in, audio out with Chat Completions. Accepts audio inputs and outputs.
128K
$2.5
$10
Feb 2026
GPT-5.3 Codex
Most capable agentic coding model. Combines frontier coding performance of GPT-5.2-Codex with reasoning and professional knowledge of GPT-5.2. ~25% faster.
400K
$1.75
$14
Feb 2026
GPT-5.2 Codex
deprecatedGPT-5.2 optimized for long-horizon, agentic coding tasks in Codex or similar environments. Supports low, medium, high, and xhigh reasoning effort settings.
400K
$1.75
$14
Dec 2025
GPT-5.2
Most capable model for professional work and long-running agents. Improvements in general intelligence, long-context, agentic tool-calling, and vision.
400K
$1.75
$14
Dec 2025
GPT-5.2 Pro
Smartest and most trustworthy option for difficult questions. Uses more compute for harder thinking on complex domains like programming.
400K
$21
$168
Dec 2025
GPT-5.2 Instant
deprecatedGPT-5.2 Instant model, previously powering ChatGPT. Replaced by GPT-5.5 Instant.
128K
$1.75
$14
Dec 2025
GPT-5.1 Codex Max
deprecatedOur most intelligent coding model optimized for long-horizon, agentic coding tasks.
400K
$1.25
$10
Nov 2025
GPT-5.1
The best model for coding and agentic tasks with configurable reasoning effort.
400K
$1.25
$10
Nov 2025
GPT-5.1 Codex Mini
deprecatedSmaller, faster version of GPT-5.1 Codex for efficient coding tasks.
400K
$0.25
$2
Nov 2025
GPT-5.1 Codex
deprecatedA version of GPT-5.1 optimized for agentic coding tasks in Codex or similar environments.
400K
$1.25
$10
Nov 2025
GPT-5.1 Instant
deprecatedGPT-5.1 Instant with adaptive reasoning. More conversational with improved instruction following.
128K
$1.25
$10
Nov 2025
GPT-5 Search API
Updated web search model in Chat Completions API. 60% cheaper with domain filtering support.
400K
$1.25
$10
Oct 2025
GPT Audio Mini
Cost-efficient audio model. Accepts audio inputs and outputs via Chat Completions REST API.
128K
$0.6
$2.4
Oct 2025
GPT-5 Pro
Version of GPT-5 that uses more compute to produce smarter and more precise responses. Designed for tough problems.
400K
$15
$120
Oct 2025
GPT-5 Codex
deprecatedA version of GPT-5 optimized for agentic coding in Codex.
400K
$1.25
$10
Sep 2025
GPT Audio
First generally available audio model. Accepts audio inputs and outputs, and can be used in the Chat Completions REST API.
128K
$2.5
$10
Aug 2025
GPT-5 Mini
A faster, more cost-efficient version of GPT-5 for well-defined tasks.
400K
$0.25
$2
Aug 2025
GPT-5 Nano
Fastest, most cost-efficient version of GPT-5 for summarization and classification tasks.
400K
$0.05
$0.4
Aug 2025
GPT-5
The best model for coding and agentic tasks across domains.
400K
$1.25
$10
Aug 2025
GPT-5 ChatGPT
deprecatedGPT-5 model used in ChatGPT.
128K
$1.25
$10
Aug 2025
o4 Mini Deep Research
deprecatedFaster, more affordable deep research model for complex, multi-step research tasks.
200K
$2
$8
Jun 2025
o3 Deep Research
deprecatedOur most powerful deep research model for complex, multi-step research tasks.
200K
$10
$40
Jun 2025
o3 Pro
Version of o3 with more compute for better responses. Provides consistently better answers for complex tasks.
200K
$20
$80
Jun 2025
o3
A well-rounded and powerful model across domains. Sets a new standard for math, science, coding, and visual reasoning tasks.
200K
$2
$8
Apr 2025
o4 Mini
deprecatedLatest o4-mini model. Optimized for fast, effective reasoning with exceptionally efficient performance in coding and visual tasks.
200K
$1.1
$4.4
Apr 2025
GPT-4.1 Nano
Fastest, most cost-effective GPT 4.1 model. Delivers exceptional performance with low latency, ideal for tasks like classification or autocompletion.
1M
$0.1
$0.4
Apr 2025
GPT-4.1 Mini
Balanced for intelligence, speed, and cost. Matches or exceeds GPT-4o in intelligence while reducing latency by nearly half and cost by 83%.
1M
$0.4
$1.6
Apr 2025
GPT-4.1
Flagship GPT model for complex tasks. Major improvements on coding, instruction following, and long context with 1M token context window.
1M
$2
$8
Apr 2025
o1 Pro
A version of o1 with more compute for better responses. Provides consistently better answers for complex tasks.
200K
$150
$600
Mar 2025
GPT-4o Mini Search Preview
deprecatedLatest snapshot of the GPT-4o Mini model optimized for web search capabilities.
128K
$0.15
$0.6
Mar 2025
GPT-4o Search Preview
deprecatedLatest snapshot of the GPT-4o model optimized for web search capabilities.
128K
$2.5
$10
Mar 2025
o3 Mini
Latest o3-mini model snapshot. High intelligence at the same cost and latency targets of o1-mini. Excels at science, math, and coding tasks.
200K
$1.1
$4.4
Jan 2025
o1
deprecatedPrevious full o-series reasoning model.
200K
$15
$60
Dec 2024
GPT-4o mini
Affordable model for fast, lightweight tasks. GPT-4o Mini is cheaper and more capable than GPT-3.5 Turbo.
128K
$0.15
$0.6
Jul 2024
GPT-4o
Snapshot of gpt-4o from November 20th, 2024.
128K
$2.5
$10
May 2024
GPT-4 Turbo
GPT-4 Turbo with Vision model. Vision requests can now use JSON mode and function calling. gpt-4-turbo currently
128K
$10
$30
Apr 2024
3.5-Turbo
The latest GPT-3.5 Turbo model with higher accuracy at responding in requested formats.
16K
$0.5
$1.5
Jan 2024
3.5-Turbo
deprecatedThe latest GPT-3.5 Turbo model with higher accuracy at responding in requested formats.
16K
$0.5
$1.5
Jan 2024
3.5-Turbo
deprecatedGPT-3.5 Turbo model with improved instruction following, JSON mode, reproducible outputs, parallel function calling, and more.
16K
$1
$2
Nov 2023
GPT-4
deprecatedSnapshot of gpt-4 from June 13th 2023 with improved function calling support. Data up to Sep 2021.
8K
$30
$60
Jun 2023
GPT-4
Snapshot of gpt-4 from June 13th 2023 with improved function calling support. Data up to Sep 2021.
8K
$30
$60
Jun 2023
GPT-5.6 Sol
NEWFlagship next-generation model. Strongest yet for agentic coding, science, and cybersecurity, with the most robust safety stack to date. 1M token context.
GPT-5.6 Terra
NEWBalanced model for efficient, high-volume everyday work. Competitive with GPT-5.5 while being 2x cheaper. 1M token context.
GPT-5.6 Luna
NEWFastest, most affordable GPT-5.6 model for high-volume work. Strong capability at the lowest cost in the family. 1M token context.
GPT-5.5
New baseline for complex production workflows. Stronger task execution, more precise tool use, more efficient reasoning with fewer tokens. 1M token context.
GPT-5.5 Pro
Most capable model for complex tasks. Uses more compute for smarter, more precise responses on the hardest problems.
GPT-5.4 Mini
Strongest mini model for coding, computer use, and subagents. GPT-5.4-class intelligence at lower cost and latency.
GPT-5.4 Nano
Cheapest GPT-5.4-class model for simple high-volume tasks like classification and data extraction.
GPT-5.4
Most capable and efficient frontier model for professional work. Native computer use, improved reasoning, coding, and agentic workflows with 1M token context.
GPT-5.4 Pro
Most capable model for complex tasks. Uses more compute for smarter, more precise responses on difficult problems.
GPT-5.3 Instant
deprecatedGPT-5.3 Instant model, previously powering ChatGPT. Replaced by GPT-5.5 Instant.
GPT Audio 1.5
Best voice model for audio in, audio out with Chat Completions. Accepts audio inputs and outputs.
GPT-5.3 Codex
Most capable agentic coding model. Combines frontier coding performance of GPT-5.2-Codex with reasoning and professional knowledge of GPT-5.2. ~25% faster.
GPT-5.2 Codex
deprecatedGPT-5.2 optimized for long-horizon, agentic coding tasks in Codex or similar environments. Supports low, medium, high, and xhigh reasoning effort settings.
GPT-5.2
Most capable model for professional work and long-running agents. Improvements in general intelligence, long-context, agentic tool-calling, and vision.
GPT-5.2 Pro
Smartest and most trustworthy option for difficult questions. Uses more compute for harder thinking on complex domains like programming.
GPT-5.2 Instant
deprecatedGPT-5.2 Instant model, previously powering ChatGPT. Replaced by GPT-5.5 Instant.
GPT-5.1 Codex Max
deprecatedOur most intelligent coding model optimized for long-horizon, agentic coding tasks.
GPT-5.1
The best model for coding and agentic tasks with configurable reasoning effort.
GPT-5.1 Codex Mini
deprecatedSmaller, faster version of GPT-5.1 Codex for efficient coding tasks.
GPT-5.1 Codex
deprecatedA version of GPT-5.1 optimized for agentic coding tasks in Codex or similar environments.
GPT-5.1 Instant
deprecatedGPT-5.1 Instant with adaptive reasoning. More conversational with improved instruction following.
GPT-5 Search API
Updated web search model in Chat Completions API. 60% cheaper with domain filtering support.
GPT Audio Mini
Cost-efficient audio model. Accepts audio inputs and outputs via Chat Completions REST API.
GPT-5 Pro
Version of GPT-5 that uses more compute to produce smarter and more precise responses. Designed for tough problems.
GPT-5 Codex
deprecatedA version of GPT-5 optimized for agentic coding in Codex.
GPT Audio
First generally available audio model. Accepts audio inputs and outputs, and can be used in the Chat Completions REST API.
GPT-5 Mini
A faster, more cost-efficient version of GPT-5 for well-defined tasks.
GPT-5 Nano
Fastest, most cost-efficient version of GPT-5 for summarization and classification tasks.
GPT-5
The best model for coding and agentic tasks across domains.
GPT-5 ChatGPT
deprecatedGPT-5 model used in ChatGPT.
o4 Mini Deep Research
deprecatedFaster, more affordable deep research model for complex, multi-step research tasks.
o3 Deep Research
deprecatedOur most powerful deep research model for complex, multi-step research tasks.
o3 Pro
Version of o3 with more compute for better responses. Provides consistently better answers for complex tasks.
o3
A well-rounded and powerful model across domains. Sets a new standard for math, science, coding, and visual reasoning tasks.
o4 Mini
deprecatedLatest o4-mini model. Optimized for fast, effective reasoning with exceptionally efficient performance in coding and visual tasks.
GPT-4.1 Nano
Fastest, most cost-effective GPT 4.1 model. Delivers exceptional performance with low latency, ideal for tasks like classification or autocompletion.
GPT-4.1 Mini
Balanced for intelligence, speed, and cost. Matches or exceeds GPT-4o in intelligence while reducing latency by nearly half and cost by 83%.
GPT-4.1
Flagship GPT model for complex tasks. Major improvements on coding, instruction following, and long context with 1M token context window.
o1 Pro
A version of o1 with more compute for better responses. Provides consistently better answers for complex tasks.
GPT-4o Mini Search Preview
deprecatedLatest snapshot of the GPT-4o Mini model optimized for web search capabilities.
GPT-4o Search Preview
deprecatedLatest snapshot of the GPT-4o model optimized for web search capabilities.
o3 Mini
Latest o3-mini model snapshot. High intelligence at the same cost and latency targets of o1-mini. Excels at science, math, and coding tasks.
o1
deprecatedPrevious full o-series reasoning model.
GPT-4o mini
Affordable model for fast, lightweight tasks. GPT-4o Mini is cheaper and more capable than GPT-3.5 Turbo.
GPT-4o
Snapshot of gpt-4o from November 20th, 2024.
GPT-4 Turbo
GPT-4 Turbo with Vision model. Vision requests can now use JSON mode and function calling. gpt-4-turbo currently
3.5-Turbo
The latest GPT-3.5 Turbo model with higher accuracy at responding in requested formats.
3.5-Turbo
deprecatedThe latest GPT-3.5 Turbo model with higher accuracy at responding in requested formats.
3.5-Turbo
deprecatedGPT-3.5 Turbo model with improved instruction following, JSON mode, reproducible outputs, parallel function calling, and more.
GPT-4
deprecatedSnapshot of gpt-4 from June 13th 2023 with improved function calling support. Data up to Sep 2021.
GPT-4
Snapshot of gpt-4 from June 13th 2023 with improved function calling support. Data up to Sep 2021.
1
Create an API key at the OpenAI console.
2
Paste it into Big-AGI's model settings.
3
Start chatting, or Beam it against other models and fuse the answers.
Add your OpenAI API key and use OpenAI's models at OpenAI's own API rates. Big-AGI isn't a reseller: no markup and no intermediary, so the bill comes straight from OpenAI to your account.
ChatGPT gives you one model in one box. Big-AGI runs OpenAI's models next to Claude, Gemini, Grok, and anything else you've connected, in the same conversation, something ChatGPT has no reason to offer.
It also hands you the dials ChatGPT hides: reasoning effort and verbosity are real parameters on OpenAI's API, not settings we invented. Your keys stay in your browser, not inside an OpenAI account. Big-AGI itself needs no account either, paste a key and start.
OpenAI bills per token too, so a light user can spend less in a month than a flat subscription, and a heavy user never hits an artificial cap, just a bill for tokens used. Beam parallel runs cost more tokens than a single ChatGPT reply, the honest tradeoff for comparing frontier models side by side.
Turn on Direct Connection under OpenAI's Advanced settings and the browser calls OpenAI directly, skipping the Big-AGI server, whenever your key lives client-side and OpenAI's API allows it. Your keys stay in your browser. Chats are stored locally first and sync only if you turn it on. The AI Inspector shows the exact request before it goes out: model, parameters, token counts, and a cost estimate.
Beam runs OpenAI's models against Claude, Gemini, or any other model you've connected, in parallel, then hands you Fusions: several strategies that combine, cross-check, and synthesize the parallel answers, which beats just picking the best one. Parallel runs use more tokens than a single chat.
Your key, your data, your choice of model. Big-AGI is open source and self-hostable, so you can check exactly how OpenAI is called.
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