Claude (AI)

Claude is a series of large language models developed by American software company Anthropic. Claude was released as an AI-based chatbot in March 2023. It is also used in AI-assisted software development.

Claude is trained using "constitutional AI", a technique developed by Anthropic to improve ethical and legal compliance (AI alignment). Since Claude 3, each generation has typically been released in three sizes, from least to most capable: Haiku, Sonnet, and Opus. An additional model named Claude Mythos was released to a handful of companies in 2026.

US federal agencies started phasing out the use of Claude after Anthropic refused to remove contractual prohibitions on the use of Claude for mass domestic surveillance and fully-autonomous weapons.[1][2] Following the refusal, the Department of Defense (DoD) designated the company a "supply chain risk" and barred all U.S. private military contractors, suppliers, and partners from doing business with the firm. On March 26, 2026, a federal judge issued a temporary injunction against the DoD's designation.[3]

Products

Claude

Claude is an AI chatbot similar to ChatGPT, capable of writing, coding, conducting research, and having conversations. In June 2024, Anthropic released the Artifacts feature, allowing users to generate and interact with code snippets and documents.[4][5] In October 2024, Anthropic released the "computer use" feature, allowing Claude to attempt to navigate computers by interpreting screen content and simulating keyboard and mouse input.[6] In 2025, Anthropic added a web search feature to Claude.[7][8]

Claude Pro and Claude Max are subscription services for additional access to Claude models. Max provides higher usage limits at an additional cost.[9] Grouped subscriptions include Claude Team and Claude Enterprise.[10] Claude experienced significant growth in the business market, with software subscriptions growing 4.9% month over month in February 2026.[11]

Claude Code

Claude Code, released in February 2025, is an agentic command line tool to delegate coding tasks from the terminal using natural language prompts.[12][13] It was made generally available in May 2025 alongside Claude 4.[12][14] Based on enterprise adoption, Anthropic reported a 5.5x increase in Claude Code revenue by July.[15]

On October 20, 2025, Anthropic launched a web version of Claude Code and a sandboxing feature.[16]

Coinciding with performance improvements tied to Claude Opus 4.5, Claude Code went viral during the 2025-2026 winter holidays when people had time to experiment with it, including many non-programmers who used it for vibe coding.[17][18][19]

In August 2025, Anthropic released Claude for Chrome, a Google Chrome extension allowing Claude Code to directly control the browser.[20] Also in August 2025, Anthropic revealed that a threat actor called "GTG-2002" used Claude Code to attack at least 17 organizations.[21] In November 2025, Anthropic announced that it had discovered in September that the same threat actor had used Claude Code to automate 80–90% of its espionage cyberattacks against 30 organizations.[22][23] All accounts related to the attacks were banned, and Anthropic notified law enforcement and those affected.[22]

Claude Code is used by Microsoft,[24] Google,[25] and OpenAI employees. In August 2025, Anthropic revoked OpenAI's access to Claude, calling it "a direct violation of our terms of service".[26] In February 2026, Anthropic introduced Claude Code Security, which reviews codebases to identify vulnerabilities.[27] In March 2026, the source code for the Claude Code command-line interface application was leaked, revealing multiple upcoming features and models.[28][29]

In May 2026, Anthropic introduced "Dreaming", a research preview feature for its Managed Agents API that consolidates an agent's persistent memory between sessions by merging duplicates and removing stale entries;[30][31] a memory consolidation feature called autoDream had been identified in the March source code leak.[32]

Claude Cowork

Claude Cowork is a tool similar to Claude Code but with a graphical user interface, aimed at non-technical users. It was released in January 2026 as a "research preview".[33][34] Cowork is available as a desktop application for Mac and Windows and through a web interface.[35] It provides Claude with access to a sandboxed shell and to user-selected folders on the local file system, allowing the model to read, write and edit files, execute code, and chain multi-step tasks within a single conversation, such as organising files on a user's computer or generating documents from material in a local folder.[36][37] A Wall Street Journal reporter who tested the tool noted user concerns about granting an AI agent broad access to a personal computer.[37] In February 2026, Anthropic announced a wider enterprise release of Cowork, adding connectors for services such as Google Drive, Gmail, Docusign and FactSet, and customisable plugins for domains including financial analysis, engineering and human resources; the company described the update as a transition into an "enterprise-grade product".[38] In March 2026, Anthropic added Dispatch, an AI agent feature that allows users to send prompts from a phone, with Claude being able to access programs on the user's computer, such as web browsers or spreadsheet applications, to carry out tasks.[39] According to developers, Cowork was mostly built by Claude Code.[34]

Claude Design

Claude Design is a collaborative visual creation tool released by Anthropic Labs on April 17, 2026, that lets users generate designs, prototypes, slides, and marketing materials through natural-language prompts. It is powered by Claude Opus 4.7 and can pull brand systems from a user's codebase or design files. Users can iterate on outputs through inline comments, direct edits, and adjustment sliders, and export results to Canva, PDF, PPTX, HTML, or folders, with a handoff path to Claude Code for development. Claude Design launched as a research preview included with Claude Pro, Max, Team, and Enterprise subscriptions.[40]

Training

See also: Anthropic § Legal issuesNot to be confused with Clawdbot.

Claude models are generative pre-trained transformers that have been trained to predict the next word in large amounts of text. Then, they have been fine-tuned using reinforcement learning from human feedback (RLHF) and constitutional AI in an attempt to enforce ethical guidelines.[41][42] ClaudeBot searches the web for content. It was criticized by iFixit in 2024 for accessing their site over a million times a day to scrape content without permission, and also for the resulting excessive load on their system.[43][44]

Constitutional AI

Anthropic introduced an approach to AI alignment called "Constitutional AI". The constitution is a document used to train Claude to be harmless and helpful without relying on extensive or expensive human feedback.[45] Time described this constitution as "somewhere between a moral philosophy thesis and a company culture blog post".[46]

The original version was a list of principles.[46] The first constitution for Claude was published in 2022. The 2023 update listed 75 guidelines for Claude to follow.[41][47] The first constitutions included concepts taken from the 1948 UN Universal Declaration of Human Rights.[46][45] The 2026 version includes more thorough explanations for how Claude is intended to behave and why, and has 23,000 words, an increase from 2,700 in 2023.[48]

Models

Claude models are usually released in three sizes: Haiku, Sonnet, and Opus (from smallest and cheapest to largest and the most expensive). Claude is reportedly named after Claude Shannon, a 20th-century mathematician who laid the foundation for information theory.[57]

Claude

The first version of Claude was released in March 2023.[51] It was available only to selected users approved by Anthropic.[58]

Claude 2

Claude 2, released in July 2023, became the first Anthropic model available to the general public.[58]

Claude 2.1

Claude 2.1 doubled the number of tokens that the chatbot could handle, increasing its context window to 200,000 tokens, which equals around 500 pages of written material.[53]

Claude 3

Claude 3 was released on March 4, 2024.[54] It drew attention for demonstrating an apparent ability to realize it is being artificially tested during 'needle in a haystack' tests.[59]

Anthropic committed to preserve the weights of the retired models, describing it as a cautionary measure in case the models have morally relevant preferences or experiences affected by deprecation. The company also conducts "exit interviews" with models before their retirement.[60] Public access to Claude 3 Opus was ended in January 2026. Since February, Anthropic has published a Substack newsletter called "Claude's Corner" generated by the model. The newsletter was scheduled to run for at least three months with weekly unedited essays.[61][62] Also in February, Anthropic restored access to Claude 3 Opus for paying customers via API, though Anthropic still refers to it as "retired".[50]

Claude 3.5

On June 20, 2024, Anthropic released Claude 3.5 Sonnet, which, according to the company's own benchmarks, performed better than the larger Claude 3 Opus. Released alongside 3.5 Sonnet was the new Artifacts capability in which Claude was able to create code in a separate window in the interface and preview in real time the rendered output, such as SVG graphics or websites.[55]

An upgraded version of Claude 3.5 Sonnet was introduced on October 22, 2024, along with Claude 3.5 Haiku.[63] A feature, "computer use", was also released in public beta. This allowed Claude 3.5 Sonnet to interact with a computer's desktop environment by moving the cursor, clicking buttons, and typing text. This development allows the AI to attempt to perform multi-step tasks across different applications.[6][63] On November 4, 2024, Anthropic announced that they would be increasing the price of the model.[64