SubSync

Tracking since Apr 4, 2026.

Changelog

• Apr 23, 2026
  description

  SubSync transforms AI conversations into a multi-threaded thinking experience.
  
  Open a synced sidebar next to ChatGPT or Claude and explore tangents, definitions, and experiments—without derailing your core conversation.
  
  Now with Prompt Improver: refine and strengthen your prompts in one click before sending, so you ask clearer, sharper questions every time.
  
  Features include real-time sync, multi-provider support, prompt enhancement, markdown formatting, and automatic conversation saving.
  
  Boost clarity. Reduce friction. Keep your flow.
  
  Permissions notice:
  Host permissions are required so SubSync can read and structure user conversations on supported pages (https://chat.openai.com/*, https://claude.ai/*). The extension only accesses these pages when the user explicitly opens it. No information is stored or sent externally without user action.

  SubSync turns AI chat into a multi-threaded workspace.
  
  Open a synced sidebar next to ChatGPT, Claude, or Gemini to explore tangents, definitions, experiments, and follow-up questions without breaking your main conversation flow.
  
  With Prompt Improver, you can rewrite prompts in one click before sending, so your requests are clearer, sharper, and easier for models to answer well.
  
  Key features:
  *Sync from selected text on supported AI pages
  *Chat Mode and Notes Mode in one sidebar
  *24-hour local conversation history with quick session switching
  *Prompt improvement before send
  *Markdown-friendly responses
  *Resizable sidebar with compact header handling at smaller widths
  *Multi-provider support with direct API mode or backend fallback
  *Optional custom model configuration
  *Boost clarity, reduce friction, and keep momentum while you think.
  
  Permissions notice:
  SubSync needs host permissions on supported AI pages to read conversation context and power Sync and Improve actions. Data is only sent when you trigger an action, such as asking in the sidebar or using Prompt Improver.

Permissions & access

Permissions

storage

Host access

https://chat.openai.com/*, https://chatgpt.com/*, https://claude.ai/*, https://gemini.google.com/*, https://subsync-backend.vercel.app/*, https://api.openai.com/*, https://api.anthropic.com/*, https://generativelanguage.googleapis.com/*, https://openrouter.ai/*, https://ai.megallm.io/*

Screenshots

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