Skip to main content
Source: OpenAI model docs · API pricing. Prices are USD per million tokens at Standard tier, checked October 3, 2026. Published post-promotion rates take precedence; promotional rates are retained when no post-promotion rates are published. Processing discounts and premiums are model-specific; see the GPT-6 notes below.

​
GPT-6 Series

gpt-6-astra

Reasoning · Speedopenai/gpt-6-astraOpenAI’s most capable model, built for the hardest end-to-end work: complex reasoning, agentic coding, computer use, research, and document creation. Successor to GPT-5.6 Sol. reasoning.effort accepts low, medium, high, xhigh, and max (API default low).
  • $10 / $50 per 1M tokens (input / output); cached input $1 / 1M; cache writes $12.50 / 1M
  • Prompts over 272K input tokens bill the full request at long-context rates: $20 / $75, cached $2, cache writes $25
  • Function tools require the Responses API (Timbal’s default). With TIMBAL_OPENAI_API=chat_completions, tool calls return 400 and reasoning_effort: "none" is rejected
  • 1.05M context
  • 128K max output
  • Text, Image input
  • Extended thinking
  • Web search
  • Knowledge cutoff Apr 30, 2026

gpt-6.1-sol

openai/gpt-6.1-solComplex coding, computer use, and professional work. Released September 29, 2026.
  • $2 input / $10 output per 1M tokens; cached input $0.10; cache writes $2.50
  • Above 272K input tokens, the full request costs $4 / $15; cached input $0.20; cache writes $5
  • 1.05M context; 128K max output; text and image input, text output
  • Reasoning: low, medium (default), high, xhigh, max; none and minimal are unsupported
  • Function tools require Responses. Chat Completions supports requests without tools
  • Model reference, crosschecked against API pricing and release notes

gpt-6-sol

openai/gpt-6-solFor complex coding and agentic workflows.
  • $2 / $10 per 1M tokens (input / output); cached input $0.20; cache writes $2.50
  • Over 272K input tokens: $4 / $15; cached input $0.40; cache writes $5, applied to the full request
  • 1.05M context
  • 128K max output
  • Text and Image input; Text output
  • Streaming, function calling, and structured outputs
  • Reasoning: none, low, medium (default), high, xhigh, max
  • Knowledge cutoff Apr 20, 2026

gpt-6-luna

openai/gpt-6-lunaFor focused tasks and high-volume workloads at low cost.
  • $0.10 / $0.50 per 1M tokens (input / output); cached input $0.01; cache writes $0.125
  • Over 272K input tokens: $0.20 / $0.75; cached input $0.02; cache writes $0.25, applied to the full request
  • 1.05M context
  • 128K max output
  • Text and Image input; Text output
  • Streaming, function calling, and structured outputs
  • Reasoning: none, low, medium (default), high, xhigh, max
  • Knowledge cutoff May 18, 2026

​
Using GPT-6.1 Sol and GPT-6

Set OPENAI_API_KEY and choose openai/gpt-6.1-sol:
Use the Responses API (Timbal’s default) for reasoning with tools. With TIMBAL_OPENAI_API=chat_completions, function calling on the older GPT-6 Sol and GPT-6 Luna requires model_params={"reasoning_effort": "none"}. GPT-6.1 Sol and Astra require Responses for tool calling. Astra and GPT-6.1 Sol offer Ultrafast at 6x Standard, including cache and long-context rates, using model_params={"service_tier": "ultrafast"}. Usage uses _ultrafast units. Sol’s Ultrafast input / output / cached input / cache writes cost $12 / $60 / $0.60 / $15 per 1M tokens; above 272K input tokens they cost $24 / $90 / $1.20 / $30 for the full request. Availability and rates rechecked October 17, 2026. All GPT-6 prices shown are Standard rates. Batch and Flex cost half the applicable rates; Fast mode costs twice as much, including cache and long-context rates. Opt into Flex or Fast with model_params={"service_tier": "flex"} or {"service_tier": "fast"}; metering follows the tier reported by the provider. Regional processing adds 10% where eligible. GPT-6 Sol and Luna support EU data residency with Standard, Flex, and Batch; Fast is unavailable there. GPT-6.1 Sol also supports EU residency without Fast. Regional premiums are not included in the catalog token rates. Sol and Luna launched September 22, 2026. Specs and prices verified September 23, 2026 against Sol’s model reference, Luna’s model reference, and OpenAI pricing.

​
How long-context and cache pricing is tracked

GPT-6.1 Sol, GPT-6 Astra/Sol/Luna, GPT-5.6 Sol/Terra/Luna, GPT-5.5/Pro, GPT-5.4 and GPT-5.4 Pro bill the entire request at long-context rates once the prompt exceeds 272K input tokens — including cache reads, cache writes, and output. (GPT-5.5 Pro also has a long-context tier in the pricing table, although its model card omits it; no cache discount is published.) Timbal’s collectors decide the tier from the raw prompt size reported by OpenAI (cache hits included; exactly 272K is still short context) and emit distinct usage units so each tier can be priced separately: input_cache_write_tokens is split out only for models whose catalog entry has a cache_write_price (OpenAI bills prompt-cache writes at 1.25x the input rate); on any other model those tokens stay in input_text_tokens so they are still billed. Reasoning tokens are folded into output_text_tokens (they are billed as output). GPT-6 responses served by Flex or Fast processing additionally use _flex or _fast (for example, output_text_tokens_long_context_fast) so the processing multiplier is preserved. Eval usage assertions treat all pricing tiers as the same underlying tokens. The per-model thresholds and tier rates live in python/timbal/models.yaml (cached_input_price, cache_write_price, long_context, service_tiers).

​
GPT-5 Series

gpt-5.5

Reasoning · Speedopenai/gpt-5.5OpenAI’s latest flagship for coding, knowledge work, and research—positioned above GPT-5.4 with a 1.05M-token API context (per OpenAI model table) and higher per-token pricing.
  • $5 / $30 per 1M tokens (input / output); cached input $0.50 / 1M
  • 1.05M context
  • 128K max output
  • Text, Image input
  • Extended thinking
  • Web search

gpt-5.5-pro

Reasoning · Speedopenai/gpt-5.5-proGPT-5.5 Pro tier for the hardest coding, agentic, and research workloads via the Responses API.
  • $30 / $180 per 1M tokens (input / output)
  • 1.05M context
  • Text, Image input
  • Extended thinking
  • Above 272K input: $60 / $270 per 1M tokens for the full request, per the pricing table

gpt-5.5-2026-04-23

Reasoning · Speedopenai/gpt-5.5-2026-04-23Dated snapshot of GPT-5.5 for reproducible runs; same capabilities and pricing as the rolling gpt-5.5 slug.
  • $5 / $30 per 1M tokens (input / output); cached input $0.50 / 1M
  • 1.05M context
  • 128K max output
  • Text, Image input
  • Extended thinking

gpt-5.6-sol

Reasoning · Speedopenai/gpt-5.6-solGPT-5.6 flagship tier for the hardest coding, agentic, and long-horizon tasks. Supports programmatic tool calling and multi-agent flows in the Responses API.
  • $4 input / $20 output per 1M tokens; cached input $0.40; cache writes $5
  • Above 272K input: $8 / $30; cached input $0.80; cache writes $10 for the full request
  • Promotional rates, available at least through November 21, 2026, retained because post-promotion rates are not published. Sources: model card, pricing table.
  • 1.05M context
  • 128K max output
  • Text, Image input
  • Extended thinking
  • Web search

gpt-5.6-terra

Reasoning · Speedopenai/gpt-5.6-terraGPT-5.6 balanced tier for everyday production work—competitive with GPT-5.5 at roughly half the cost of Sol.
  • $2 / $12 per 1M tokens (input / output); cached input $0.20 / 1M
  • 1.05M context
  • 128K max output
  • Text, Image input
  • Extended thinking
  • Web search

gpt-5.6-luna

Reasoning · Speedopenai/gpt-5.6-lunaGPT-5.6 fast, cost-efficient tier for high-volume, latency-sensitive, and budget-conscious workloads.
  • $0.20 / $1.20 per 1M tokens (input / output); cached input $0.02 / 1M
  • 1.05M context
  • 128K max output
  • Text, Image input
  • Extended thinking
  • Web search

gpt-5.4

Reasoning · Speedopenai/gpt-5.4OpenAI’s most capable and efficient frontier model for professional work, combining industry-leading coding, reasoning, and agentic workflows with native computer-use capabilities.
  • $2.50 / $15
  • 1.05M context
  • 128K max output
  • Text, Image input
  • Extended thinking
  • Web search
  • Knowledge cutoff Aug 2025
  • Cached input: $0.25 per 1M tokens

gpt-5.4-pro

Reasoning · Speedopenai/gpt-5.4-proGPT-5.4 Pro tier for maximum capability coding and agent workloads via the Responses API.
  • $30 / $180 per 1M tokens (input / output)
  • 1.05M context
  • Text, Image input
  • Extended thinking

gpt-5.4-mini

Reasoning · Speedopenai/gpt-5.4-miniOpenAI’s most capable small model, significantly improving over GPT-5 mini across coding, reasoning, multimodal understanding, and tool use while running more than 2x faster.
  • $0.75 / $4.50
  • 400K context
  • 128K max output
  • Text, Image input
  • Thinking
  • Web search
  • Knowledge cutoff Aug 2025
  • Cached input: $0.075 per 1M tokens

gpt-5.4-nano

Reasoning · Speedopenai/gpt-5.4-nanoDeprecated October 1, 2026; scheduled retirement April 1, 2027. Migrate before that date.The smallest, cheapest version of GPT-5.4 for tasks where speed and cost matter most. Ideal for classification, data extraction, ranking, and coding subagents.
  • $0.20 / $1.25
  • 400K context
  • 128K max output
  • Text, Image input
  • Knowledge cutoff Aug 2025
  • Cached input: $0.02 per 1M tokens

gpt-5.2

Reasoning · Speedopenai/gpt-5.2The most capable model series for professional knowledge work, with significant improvements in general intelligence, long-context understanding, agentic tool-calling, and vision.
  • $1.75 / $14
  • 400K context
  • 128K max output
  • Text, Image input
  • Thinking
  • Web search
  • Knowledge cutoff Aug 2025
  • Cached input: $0.175 per 1M tokens

gpt-5.2-pro

Reasoning · Speedopenai/gpt-5.2-proA version of GPT-5.2 that uses more compute to think harder and provide consistently better answers for complex tasks.
  • $21 / $168
  • 400K context
  • 128K max output
  • Text, Image input
  • Thinking
  • Web search
  • Knowledge cutoff Aug 2025

gpt-5.1

Reasoning · Speedopenai/gpt-5.1Deprecated October 1, 2026; scheduled retirement April 1, 2027. Migrate before that date.Improves meaningfully on both intelligence and communication style; the first model to use adaptive reasoning to decide when to think before responding.
  • $1.25 / $10
  • 400K context
  • 128K max output
  • Text, Image input
  • Thinking
  • Web search
  • Knowledge cutoff Sep 2024
  • Cached input: $0.125 per 1M tokens

gpt-5

Reasoning · Speedopenai/gpt-5OpenAI’s unified AI system representing a significant leap in intelligence, with a smart efficient model for most questions and a deeper reasoning model for harder problems.
  • $1.25 / $10
  • 400K context
  • 128K max output
  • Text, Image, Audio, Video input
  • Thinking
  • Web search
  • Knowledge cutoff Sep 2024
  • Cached input: $0.125 per 1M tokens

gpt-5-mini

Reasoning · Speedopenai/gpt-5-miniA smaller, faster variant of GPT-5’s thinking model optimized for developer use, balancing strong reasoning with lower cost and latency.
  • $0.25 / $2
  • 400K context
  • 128K max output
  • Text, Image input
  • Web search
  • Knowledge cutoff May 2024
  • Cached input: $0.025 per 1M tokens

gpt-5-nano

Reasoning · Speedopenai/gpt-5-nanoThe smallest and fastest variant in the GPT-5 family, made for developers needing maximum speed at minimal cost.
  • $0.05 / $0.40
  • 400K context
  • 128K max output
  • Text, Image input
  • Knowledge cutoff May 2024
  • Cached input: $0.005 per 1M tokens

​
GPT-4 Series

gpt-4.1

Reasoning · Speedopenai/gpt-4.1Excels at instruction following and tool calling with broad knowledge, featuring a 1M token context window and low latency without a reasoning step.
  • $2 / $8
  • 1.05M context
  • 32K max output
  • Text, Image input
  • Web search
  • Knowledge cutoff Jun 2024
  • Cached input: $0.5 per 1M tokens

gpt-4.1-mini

Reasoning · Speedopenai/gpt-4.1-miniA significant leap in small model performance that matches or exceeds GPT-4o in intelligence evals while reducing latency by nearly half and cost by 83%.
  • $0.40 / $1.60
  • 1M context
  • 32K max output
  • Text, Image input
  • Web search
  • Knowledge cutoff Jun 2024
  • Cached input: $0.1 per 1M tokens

gpt-4.1-nano

Reasoning · Speedopenai/gpt-4.1-nanoOpenAI’s fastest and cheapest model with a 1M token context window, ideal for classification and autocompletion tasks.
  • $0.10 / $0.40
  • 1M context
  • 32K max output
  • Text, Image input
  • Web search
  • Knowledge cutoff Jun 2024
  • Cached input: $0.025 per 1M tokens

gpt-4o

Reasoning · Speedopenai/gpt-4oAn autoregressive omni model that accepts any combination of text, audio, image, and video inputs, trained end-to-end across modalities.
  • $2.50 / $10
  • 128K context
  • 16K max output
  • Text, Image, Audio input
  • Knowledge cutoff Jun 2024
  • Cached input: $1.25 per 1M tokens

gpt-4o-mini

Reasoning · Speedopenai/gpt-4o-miniA fast, affordable small model for focused tasks that accepts text and image inputs at a fraction of the cost of frontier models.
  • $0.15 / $0.60
  • 128K context
  • 16K max output
  • Text, Image input
  • Knowledge cutoff Oct 2023
  • Cached input: $0.075 per 1M tokens

​
o-Series (Reasoning)

o4-mini

Reasoning · Speedopenai/o4-miniA smaller reasoning model optimized for fast, cost-efficient reasoning with exceptional performance in math, coding, and visual tasks.
  • $1.10 / $4.40
  • 200K context
  • 100K max output
  • Text, Image input
  • Thinking
  • Web search
  • Knowledge cutoff Jun 2024
  • Cached input: $0.275 per 1M tokens

o3

Reasoning · Speedopenai/o3OpenAI’s most powerful reasoning model that pushes the frontier across coding, math, science, and visual perception, ideal for complex queries requiring multi-faceted analysis.
  • $2 / $8
  • 200K context
  • 100K max output
  • Text, Image input
  • Thinking
  • Web search
  • Knowledge cutoff Jun 2024
  • Cached input: $0.5 per 1M tokens

o3-mini

Reasoning · Speedopenai/o3-miniThe most cost-efficient model in OpenAI’s reasoning series, delivering o1-level STEM performance with lower cost and faster speed.
  • $1.10 / $4.40
  • 200K context
  • 100K max output
  • Text input
  • Thinking
  • Knowledge cutoff Oct 2023
  • Cached input: $0.55 per 1M tokens

o3-pro

Reasoning · Speedopenai/o3-proA version of o3 designed to think longer and provide the most reliable, thoroughly reasoned responses for maximum performance on complex tasks.
  • $20 / $80
  • 200K context
  • 100K max output
  • Text, Image input
  • Thinking
  • Web search
  • Knowledge cutoff Jun 2024

o1

Reasoning · Speedopenai/o1OpenAI’s first reasoning model, trained to think before answering by producing a long internal chain of thought, with strong performance in science, coding, and math.
  • $15 / $60
  • 200K context
  • 100K max output
  • Text, Image input
  • Thinking
  • Knowledge cutoff Oct 2023
  • Cached input: $7.5 per 1M tokens
Reasoning tokens are billed as output tokens on all o-series models.

​
Retirement review — October 3, 2026

The active catalog no longer includes gpt-5.1-codex, o3-deep-research, or o4-mini-deep-research: their aliases and snapshots shut down July 23, 2026. OpenAI recommends GPT-5.6 Sol as the replacement. GPT-4.1 Nano, o1, o3 Mini, and o4 Mini remain listed until their October 23, 2026 shutdown. GPT-5.1 and GPT-5.4 Nano remain available until April 1, 2027. A newer generation alone is not a retirement notice. See OpenAI deprecations. Specialized audio, image, Live, and restricted-access research models need their own endpoints and billing units; they are not general Agent text-model additions. Availability here reflects public documentation, not an authenticated access check for your account.