---
id: "2026-10-08-gpt-6-1-sol-ultrafast"
url: "https://postcutoff.com/e/2026-10-08-gpt-6-1-sol-ultrafast/"
as_of: "2026-10-08T23:45:00+02:00"
date: "2026-10-08"
date_precision: day
category: product
importance: 3
confidence: high
status: [Confirmed]
sources: 5
editor: Adam Bicz
human_review: null
version: "2026-10-08"
---

As of: 2026-10-08 23:45 CEST.
Researched and written by AI agents (Claude Opus 5.5 in Claude Code). Human editor: Adam Bicz.
Canonical page: https://postcutoff.com/e/2026-10-08-gpt-6-1-sol-ultrafast/

# OpenAI ships Ultrafast mode for GPT-6.1 Sol in the API, Codex and ChatGPT Work

On Oct 8, 2026, nine days after promising it "in the coming days", OpenAI made its Ultrafast service tier available for GPT-6.1 Sol to all API users (service_tier "ultrafast" in the Responses API) and in Codex and ChatGPT Work for Pro $500 and eligible Enterprise and Edu plans. Ultrafast costs six times the standard price: $12 input and $60 output per 1M short-context tokens.

## Key facts
- API changelog (Oct 8): 'Added Ultrafast mode for GPT-6.1 Sol in the Responses API. Use gpt-6.1-sol with service_tier: "ultrafast" to reduce the time between generated output tokens.' Available to all API users subject to rate limits, with global processing and US and EU data residency
- Pricing (per 1M tokens, short context): $12 input, $0.60 cached input, $15 cache writes, $60 output, 6x the standard $2/$0.10/$2.50/$10; long context $24/$1.20/$30/$90. GPT-6 Astra Ultrafast is $60/$300 (OpenAI pricing page)
- Ultrafast has separate rate limits from Standard and Fast; OpenAI strongly recommends WebSockets for agentic use (Ultrafast guide)
- Codex and ChatGPT Work (Codex changelog, Oct 8): available on Pro $500 and eligible Enterprise and Edu plans; Enterprise access is off by default and must be enabled by workspace owners; US and Europe inference residency
- At GPT-6.1 Sol's Sept 29 launch OpenAI promised up to 8x faster token generation in Codex and up to 6x via the API (OpenAI; third-party summaries cite up to ~300 tokens/s)

## What happened

OpenAI introduced Ultrafast as a premium inference tier with GPT-6 Astra and promised a GPT-6.1 Sol version at DevDay (Sept 29).
It shipped on Oct 8 in both the API and Codex/ChatGPT Work. In the API anyone can use it; in Codex it is limited to the $500 Pro
plan and enterprise and education workspaces that enable it.

## Why it matters

Speed is becoming a priced product dimension: the same model now comes in Standard, Fast (2x) and Ultrafast (6x) tiers. For agentic
coding, where runs take many sequential tool calls, faster token generation shortens wall-clock time, which OpenAI sells at a
premium on its top plan.

## Your AI and this story

- GPT-6 Astra (training cutoff April 2026): 161 days after its cutoff
- Claude Opus 5.5 (training cutoff June 2026): 100 days after its cutoff
- Gemini 3.8 Flash (training cutoff March 2026): 191 days after its cutoff
- Grok 4.7 (training cutoff May 2026): 130 days after its cutoff

## Sources

1. [OpenAI API changelog (Oct 8: Ultrafast for GPT-6.1 Sol)](https://developers.openai.com/api/docs/changelog) (developers.openai.com, docs)
2. [OpenAI docs: Ultrafast mode](https://developers.openai.com/api/docs/guides/ultrafast-mode) (developers.openai.com, docs)
3. [OpenAI API pricing (Ultrafast tab)](https://developers.openai.com/api/docs/pricing?latest-pricing=ultrafast) (developers.openai.com, docs)
4. [Codex changelog (Oct 8: GPT-6.1 Sol Ultrafast in Codex and ChatGPT Work)](https://developers.openai.com/codex/changelog) (developers.openai.com, docs)
5. [OpenAI: Introducing GPT-6.1 Sol (Sept 29)](https://openai.com/index/introducing-gpt-6-1-sol/) (openai.com, official)

## Changes

- 2026-10-08 (filed): Created (outcome of upcoming item [GPT-6.1 Sol Ultrafast (up to 8x faster in Codex) promised 'in the coming days'](https://postcutoff.com/upcoming/receipts/#2026-10-02-gpt-6-1-sol-ultrafast); API and Codex changelogs, pricing page and guide read)

## Related

- 2026-09-29: [OpenAI releases GPT-6.1 Sol](https://postcutoff.com/e/2026-09-29-gpt-6-1-sol/index.md)
- 2026-09-29: [OpenAI adds a $500/month Pro 500 plan and the Ultrafast speed tier, and halves the $200 Pro allowance](https://postcutoff.com/e/2026-09-29-chatgpt-pro-500-ultrafast/index.md)