A/B list splitter

List / data tools

Paste a list and split it into A/B or N groups by ratio — stable order or a reproducible shuffle. Everything runs in your browser; your data is never uploaded.

What is this A/B list splitter?

A free, browser-based tool that splits a pasted list into A/B — or any number of — groups by the ratios you choose. Use stable order to keep your input order and split top-down, or shuffle with a seed for a reproducible random split. It's built for marketers running A/B tests, carving out holdout groups, or dividing a contact list evenly across owners. Everything runs locally in your browser, so your list is never uploaded.

How to use it

  1. Paste your list into the box on the left, one item per line.
  2. Set the number of groups and each group's ratio (for example 1:1 for an even A/B split).
  3. Choose stable order, or turn on shuffle and set a seed for a reproducible random split.
  4. Copy or download each group from the right with its own buttons.

Common use cases

  • Splitting an email list into A/B groups to test two subject lines.
  • Carving out a holdout group to measure the incremental impact of a campaign.
  • Dividing a lead list evenly among sales reps.

Other list tools

Operated by

unbounded pioneering inc
Timothe AI

Tools by Timothe AI is a suite of free tools built and operated by unbounded pioneering inc, the company behind Timothe AI.

Ryosuke Suzuki
Ryosuke SuzukiFounder & CEO

Founder & CEO of Unbounded Pioneering Inc., the company behind Timothe AI, and an expert in machine learning and AI product development. He began his career in machine learning research at a university laboratory, then designed and built large-scale products as a software engineer at PLAID, Rakuten, and Recruit, while also driving new business development. Now specializing in generative AI and AI products, he works across both engineering and business development, and is a named inventor on multiple granted patents in web technology.

Named inventor on granted patents JP6887648 & JP7480958 · Patent pending on Timothe AI technology

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