companies

Sider

Bootstrapped maker of the Sider AI sidebar for Chrome and Edge, letting users chat, summarize, and write against any webpage using multiple frontier models.

Sider builds an AI assistant that lives in a browser sidebar, so users can summarize articles, translate pages, chat over PDFs, and draft text without leaving the tab they are on. Rather than tying itself to one model, the extension lets people switch between OpenAI, Anthropic, and Google models on a credit system, plus screenshot-based 'ChatScreen' capture and a group-chat mode that queries several models at once. The company launched in 2023 and grew almost entirely through the Chrome Web Store and word of mouth, reaching millions of monthly users and finishing third on Product Hunt's 2025 annual leaderboard. It is notable for scaling to roughly $7M in annual revenue without raising outside capital, and it ships parallel apps for Safari, iOS, Android, Mac, and Windows alongside the flagship browser extension. Sider is run by CEO Joel Liu with co-founder Rick Fan, and operates out of the Boston area (Medford, Massachusetts). The team has grown into the 51-200 range while remaining privately held and self-funded.

Founded

2023

Headquarters

Medford, United States

Sector

applications