Switching between AI platforms usually means rebuilding your custom setups from scratch. GPT2Skill is a new browser-based tool that takes your ChatGPT Custom GPT configuration and converts it into a Claude Skill you can upload directly.
The process is straightforward: copy your GPT's name, description, instructions, and conversation starters from ChatGPT's editor, paste them into GPT2Skill, optionally upload any knowledge files (PDFs, CSVs, markdown, JSON), and download a ZIP file structured as a Claude Skill. The tool handles small but important translations automatically, like swapping "You are a GPT" to "You are a skill" in the instruction text. A live preview lets you check the converted SKILL.md before downloading.
Everything runs client-side in a single HTML file with no backend. Your instructions and knowledge files never leave your browser, which matters if your custom GPTs contain proprietary workflows or sensitive data.
The tool supports the same file types Claude Skills accept as reference materials and tracks capability flags for web search and code execution compatibility. It is free to use, though licensing details are not specified on the site.
For anyone who has built up a library of Custom GPTs and wants to try Claude's skill system without manually rewriting everything, this saves a solid chunk of tedious copy-paste work. The conversion is not going to be perfect for complex GPTs with API actions or advanced function calling, but for instruction-heavy GPTs with knowledge bases, it should get you 90% of the way there.