OpenAI ships GPT-5.5 Instant. Anthropic just overtook them on ARR.

OpenAI announced GPT-5.5 Instant on May 5 [OpenAI news]. In the same news cycle, Anthropic's reported ARR of $30B passed OpenAI's $24B — the first time the gap has flipped [Kursol].

── What shipped ──

GPT-5.5 Instant is a faster, cheaper variant of the GPT-5.5 line, optimised for low-latency interactive use cases. Pricing and capability deltas vs. the standard tier were not detailed in the announcement [LLM stats].

The Anthropic figure comes from the same April–May reporting cycle that disclosed the $200B Google TPU commitment. OpenAI's $24B figure is widely sourced but un-confirmed by the company.

── Why it matters ──

The headline release of GPT-5.5 Instant is incremental. The cheap-fast tier was inevitable; almost every frontier vendor now ships one.

The interesting number is the ARR inversion.

OpenAI has had the consumer brand. Anthropic has been quieter and more developer-focused. If the revenue gap has actually flipped, the story for the next 12 months is whether Anthropic can hold a developer-mix lead while OpenAI defends its consumer surface.

For shipping engineers, two practical effects:

• API competition stays high. Both vendors will continue undercutting each other on the cheap-fast tier. Multi-vendor abstraction layers (LiteLLM, OpenRouter, vendor-neutral SDKs) get more useful, not less.
• Vendor lock-in arguments are weaker. When the leader and the runner-up are this close on revenue, neither can credibly claim category capture. Architecting for swap-out is cheap insurance.

── Editor's take ──

GPT-5.5 Instant is a checkbox release. The ARR number — if it holds up to audited disclosure — is the genuinely consequential signal. It says the API business is bigger than the consumer business inside Anthropic, and that mix is now winning. The question to watch is whether OpenAI shifts emphasis back toward developers or doubles down on consumer.