Anthropic, OpenAI and Google build the three most cited model families today: Claude, GPT and Gemini. Each company gets its own article here: who it is, how it got here, which products it offers and what is known about its architecture.
The three articles follow the same structure so you can compare them calmly: who the company is, the timeline, the products, the architecture and training, and what to look at before choosing. Every statement comes from a source listed at the end of the page.
One rule applies to all of them: when a company does not disclose something, such as the parameter count, training data or full architecture, the text says it is not public instead of guessing. Performance numbers quoted are always the company’s own.
An AI research and products company created in 2021, organized as a public benefit corporation and maker of the Claude family, Claude Code and the Agent Skills standard.
All three systems descend from the transformer, the architecture introduced in 2017 in the paper “Attention Is All You Need”, written by Google researchers. Broadly, the process is similar: pretraining on large amounts of text to predict the next token, followed by tuning steps so the model follows instructions, refuses harmful requests and reasons better.
The differences show up in strategy and product. Editorial reading: Anthropic stresses safety and alignment research, with a strong focus on code, documents and agents; OpenAI popularized the general-purpose assistant with ChatGPT and a broad platform; Google builds Gemini into its ecosystem (Search, Android, Workspace, Cloud) and designs multimodal models from the start.
What is public about each architecture
Criterion
Claude (Anthropic)
GPT (OpenAI)
Gemini (Google)
Current family (Oct. 2026)
Haiku 5.5, Sonnet 5.5 and Opus 5.5, plus higher tiers with restricted access
GPT-6 (Astra, Sol, Luna and Instant)
Gemini 4 Argon and the 3.x series (Pro, Flash)
Technical base
Transformer trained to predict the next token
Decoder-only transformer, pretrained to predict the next token
Decoder-only transformer, optimized for Google’s TPUs
Alignment
Reinforcement learning from human feedback (RLHF) and Constitutional AI
RLHF; reasoning models trained with reinforcement learning
Adversarial training and a misalignment monitor cited for Argon
Modalities
Text and images; computer use via API
Text, image and audio (from GPT-4o onward)
Native: text, image, audio, video and code
Long context
200,000 tokens since Claude 2.1 (2023); varies by model
Not detailed in the sources consulted
Up to 1 million tokens (Gemini 1.5 Pro, 2024; Argon in the API)
Not disclosed
Parameters, training data and full architecture
Parameters, data and architecture since GPT-4 (2023)