Redis Array Playground

Simon Willison's Blog Tools
redis array playground open-source wasm database data-type

Summary

A new array data type is being added to Redis via a PR, and an interactive WASM-based playground has been built to experiment with the new commands.

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Cached at: 05/08/26, 06:45 AM

# Tool: Redis Array Playground Source: [https://simonwillison.net/2026/May/4/redis-array/](https://simonwillison.net/2026/May/4/redis-array/) Salvatore Sanfilippo submitted[a PR](https://github.com/redis/redis/pull/15162)adding a new data type \- arrays \- to Redis\. The new commands are`ARCOUNT`,`ARDEL`,`ARDELRANGE`,`ARGET`,`ARGETRANGE`,`ARGREP`,`ARINFO`,`ARINSERT`,`ARLASTITEMS`,`ARLEN`,`ARMGET`,`ARMSET`,`ARNEXT`,`AROP`,`ARRING`,`ARSCAN`,`ARSEEK`,`ARSET`\. The implementation is currently available in a branch, so I[had Claude Code for web](https://github.com/simonw/tools/pull/277)build this interactive playground for trying out the new commands in a WASM\-compiled build of a subset of Redis running in the browser\. ![Screenshot of a Redis command builder UI. Left sidebar shows commands ARSCAN, ARSEEK, ARSET. Main panel has a "predicate oneof" section with a MATCH dropdown and value CHERRY, plus a "+ add another" button. Below is "options (optional) oneof" with checkboxes: AND (checked), OR (unchecked), LIMIT (checked, value 10), WITHVALUES (checked), NOCASE (checked). COMMAND section shows: ARGREP myarr - + MATCH CHERRY AND LIMIT 10 WITHVALUES NOCASE. A red "Run command" button is below. REPLY section shows "(no reply yet)".](https://static.simonwillison.net/static/2026/redis-array-explorer-card.jpg) The most interesting new command is`ARGREP`which can run a server\-side grep against a range of values in the array using the newly vendored[TRE regex library](https://github.com/laurikari/tre/)\. Salvatore wrote more about the AI\-assisted development process for the array type in[Redis array type: short story of a long development](https://antirez.com/news/164)\.

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