Pause Giant AI Experiments: An Open Letter

Future of Life Institute · 22 March 2023

Open letterStalled

A 2023 letter asking labs to stop training systems more powerful than GPT-4 for six months. No lab paused, and several signatories went on to build bigger models, but it made AI risk a mainstream political topic.

What it calls for

  • Pause/moratorium
  • Safety evaluations
  • International governance
  • Liability
  • Compute governance
  • Transparency

Scope

30,000+ signatories incl. Bengio, Russell, Musk, Wozniak, Harari

What actually happened

No lab paused; Musk founded xAI in July 2023 and OpenAI, Google, Anthropic and Meta all trained larger models (GPT-5 shipped August 2025) (https://en.wikipedia.org/wiki/Pause_Giant_AI_Experiments:_An_Open_Letter). When the six months expired FLI pivoted to calling for regulation (https://futureoflife.org/ai/six-month-letter-expires/). The letter spawned the PauseAI movement (https://pauseai.info/) and FLI's 2025 Statement on Superintelligence. Looked for: any documented training pause by a signatory company - none.