Perplexity is a language-model evaluation metric derived from average cross-entropy loss. Intuitively, it reflects how many plausible choices the model appears to consider at each step; lower perplexity means the model assigns higher probability to the observed sequence. It is useful for comparing similar models on the same tokenized dataset, but it is not directly comparable across different vocabularies, tokenizers, or evaluation procedures. A lower score does not necessarily mean responses are more factual, helpful, safe, or preferred by people. Data contamination can also produce deceptively strong results. Perplexity is best treated as a training and predictive-fit measure alongside task-specific and human evaluations.
OpenAI’s annualized revenue was nearing $50 billion, below earlier reports near $70 billion. Different treatment of partner sales helps explain the gap.
Anthropic’s new policy bans extreme, repeated abuse of Claude from November 12, while excluding ordinary frustration, disagreement, fiction and testing.
Jeff Bezos says AI could let families live on one income or work three days a week, but has offered no timetable or plan for sharing the gains.
Claude Haiku 5.5 cuts costs for everyday AI tasks, with API rates up to 20x below Sonnet and Anthropic-reported benchmark gains over GPT-6 Luna.
Google’s SynthID Detector is now available globally for image, video and audio checks. It detects supported AI watermarks, rather than proving a file is real.
Google Playground turns prompts into browser games without coding. Unity Spark will add a more advanced creation path, with a closed beta coming soon.
Google’s Nano Banana 2.1 improves image quality, text and editing consistency while cutting its image-output token price to a quarter of Nano Banana Pro’s rate.
OpenAI will watermark eligible ChatGPT and Codex text in the EU, but restricted detector access and editing-related limitations complicate the promise of identifying AI writing.
Google unveils Gemini 4 Argon, its most powerful AI model yet, with a one-million-token output limit, introductory API pricing, and a phased rollout.
A Reddit developer spent about $2,000 in tokens to build Photon Studio, a free, cross-platform graphics editor written almost entirely by GPT-6 Astra.