OpenAI

OpenAI is the company that launched the modern AI era with ChatGPT in November 2022. On June 26, 2026 it previewed GPT-5.6 as a three-model family (Sol, Terra, Luna) under a US Government limited-preview arrangement, then made all three tiers generally available on July 9, 2026. Pricing has moved twice since. The July 30 cut dropped Luna 80 percent to $0.20 per 1M input and $1.20 output and Terra 20 percent to $2 / $12, leaving the flagship untouched. The August 21 cut finally reached Sol: $4 per 1M input (down from $5), $20 output (down from $30), and $0.40 cached input, the first move on the flagship rate since GPT-5.5 set $5 / $30 in April 2026. OpenAI lists the Sol rate as promotional through at least November 21, 2026, and it applies to the pay-as-you-go API, Codex credits, and eligible ChatGPT Work plans but not to Pro, Plus, or Business subscriptions. In ChatGPT, Free and Go users default to Terra while paid users default to Sol. GPT-5.5 (April 2026) remains broadly available with a 1M context window at the old $5 / $30. GPT-4.5 was removed from ChatGPT on June 26, 2026, following GPT-5.2 Instant, Thinking, and Pro on June 12. OpenAI operates the largest AI developer ecosystem with broad third-party integrations, plugins, and the most recognizable consumer AI brand in the world.