[Home](./index.md) > [puppeteer](./puppeteer.md) > [Protocol](./puppeteer.protocol.md) > [Runtime](./puppeteer.protocol.runtime.md) > [EntryPreview](./puppeteer.protocol.runtime.entrypreview.md) > [key](./puppeteer.protocol.runtime.entrypreview.key.md) ## Protocol.Runtime.EntryPreview.key property Preview of the key. Specified for map-like collection entries. Signature: ```typescript key?: ObjectPreview; ```