GPT-5: What It Actually Changed, and Where It Stands Now
GPT-5 launched on August 7, 2025 as OpenAI's first unified model, pairing a fast model with a reasoning model behind an automatic router and a 400,000 token context. A year on, the generation has run through GPT-5.4, GPT-5.5 and GPT-5.6 Sol, and was superseded by GPT-6 Astra on September 3, 2026. This is what genuinely changed, what was marketing, and which model is worth using now. Sources: OpenAI, TechCrunch, InfoQ.
The context
GPT-5 arrived on August 7, 2025, wrapped in the usual launch apparatus: a livestream, a wall of superlatives, and a chorus declaring everything had changed. A year later it is possible to answer the more useful question, which is what was actually different once you sat down and used it.
The structural change was the router. Before GPT-5, you chose between the fast GPT-series models and the slower o-series reasoning models yourself. GPT-5 unified them, putting a real-time router in front that decided per request whether to answer immediately or to think first. It shipped with a 400,000 token context window and pricing aggressive enough that InfoQ described the launch as commoditising, which mattered more to the industry than any benchmark did.
Everything else was refinement, and the refinements were the boring, valuable kind. GPT-5 tripped less often on multi-step reasoning, held more context in a single conversation, and called external tools more reliably. If your work leaned on those things, you felt it. If you mostly asked it to rewrite a paragraph, you struggled to tell it apart from what came before, and that is simply how mature technology improves: in increments, not miracles.
The generation then iterated harder than any before it, through GPT-5.4, GPT-5.5 and finally GPT-5.6 Sol, with code-specialised variants like GPT-5.3-Codex alongside. It ended on September 3, 2026, when GPT-6 Astra took the flagship slot with a 1,050,000 token window, much stronger long-context retrieval, and five explicit reasoning-effort settings replacing the router’s binary call.
None of which makes GPT-5 obsolete in practice. The current flagship costs $10 per million input tokens and $50 per million output, and a great deal of real work, summarising, extraction, classification, routine drafting, does not need it. The sensible pattern in late 2026 is to route by task: cheap models for the volume, the expensive one for long agent runs and genuinely hard reasoning. That was the right advice at the GPT-5 launch too. Run the model on the work you actually do, compare it honestly against what you already use, and let the results rather than the keynote decide. Sources: TechCrunch, InfoQ, OpenAI, OpenRouter.
People also ask
True or false?
August 7, 2025, in a livestreamed launch, with access ramping across tiers for weeks afterwards. (TechCrunch)
GPT-6 Astra took that spot on September 3, 2026, after the GPT-5.4, 5.5 and 5.6 Sol updates. (CNBC)
It was a consolidation: one router in front of a fast model and a reasoning model. Real gains on multi-step reliability, no change of species. (InfoQ)
400,000 at launch. The million-token window arrived with GPT-6 Astra a year later. (InfoQ, OpenRouter)
Price. The current flagship runs $10 per million in and $50 per million out, which is poor value for short prompts and routine extraction. (OpenRouter)
They got it with throttled limits, which is the usual arrangement: paid tiers buy headroom and early access rather than exclusivity. (OpenAI)