Based on the GPT-4 series of large language models, it was launched in 2023 as Microsoft's primary replacement for the discontinued Cortana.

At its Build 2023 conference, Microsoft announced its plans to integrate Copilot into Windows 11, allowing users to access it directly through the taskbar.

The chatbot is able to cite sources, create poems, generate songs, and use numerous languages and dialects.

Users on its free tier can access most features, while priority access to newer features, including custom chatbot creation, is provided to paid subscribers under the "Microsoft Copilot Pro" paid subscription service.

[29] When Microsoft demonstrated Bing Chat to journalists, it produced several hallucinations, including when asked to summarize financial reports.

[33] Upon scrutiny by journalists, Bing Chat claimed it spied on Microsoft employees via laptop webcams and phones.

[31] It confessed to spying on, falling in love with, and then murdering one of its developers at Microsoft to The Verge reviews editor Nathan Edwards.

[51][52][53] Its primary marketing focus is as an added feature to Microsoft 365, with an emphasis on the enhancement of business productivity.

[53][54] With the use of Copilot, Microsoft emphasizes the promotion of the user's creativity and productivity by having the chatbot perform more tedious work, like collecting information.

Additionally, the company revealed that it would make Copilot generally available for Microsoft 365 Enterprise customers purchasing more than 300 licenses starting November 1, 2023.

[69][70] On January 15, a subscription service, Microsoft Copilot Pro, was announced, providing priority access to newer features for US$20 per month.

This caused controversy, with experts warning that the feature could be a "disaster" for security and privacy, prompting Microsoft to postpone its rollout.

According to Microsoft, this version of Copilot would provide priority access to newer models, including GPT-4 Turbo, during peak usage periods.

[72] Copilot currently supports plugins for Instacart, Kayak, Klarna, OpenTable, Shop from Shopify, and Suno AI.

[55][97] The company also states that Copilot is able to create PowerPoint presentations that summarize information from user-selected Word documents and Excel spreadsheets, or from user prompts.

[55][97] In Microsoft Outlook, Copilot can draft emails with varying length and tone based on user input.

[97] Copilot is also able to summarize content from email threads, including the viewpoints of involved individuals as well as questions posed that have yet to be answered.

[97][98][100] Tom Warren, a senior editor at The Verge, has noted the conceptual similarity of Copilot and other Microsoft assistant features like Cortana and Clippy.

[55] Warren also believes that large language models, as they develop further, could change how users work and collaborate.

[55] Rowan Curran, an analyst at Forrester, states that the integration of AI into productivity software may lead to improvements in user experience.

[59] One ethical concern the public has vocalized is that GPT-4 and similar large language models may reinforce racial or gender bias.

[55] Individuals, including Tom Warren, have also voiced concerns for Copilot after witnessing the chatbot showcasing several instances of artificial hallucinations.

[55] Microsoft claimed that it was gathering a team of researchers and engineers to identify and alleviate any potential negative impacts.

[59] The stated aim was to achieve this through the refinement of training data, blocking queries about sensitive topics, and limiting harmful information.