Shuffle Lines

How Shuffle Lines works

Randomise the order of lines in a list, with an option to keep or drop blank lines. Everything happens inside this page: the tool reads your input, runs the calculation or conversion locally, and hands the result back to you. Nothing is transmitted, because there is no backend to transmit it to.

That design choice is deliberate. Most free tool sites upload your files to a server, process them there, and quietly keep a copy. Toolcin cannot do that — the site is a set of static files. If your connection dropped the moment the page finished loading, every tool would still work.

A real shuffle, not a sort with a random key

The list is shuffled with the Fisher–Yates algorithm, which swaps each element with a random one that has not been placed yet. Every ordering is equally likely.

The naive alternative — sorting by Math.random() — looks random and is not: some orderings become far more likely than others, and the bias is invisible in a short list.

Blank lines

By default blank lines are removed before shuffling, because a blank line in a list is usually a formatting artefact rather than an item. Turning the option on keeps them in the pool, so they end up in random positions in the output.

For a list of names or tasks, leave it off. For a file where blank lines carry meaning, turn it on.

Independent runs

Each click produces a new ordering with no memory of the previous one. Shuffling twice does not guarantee a different result — with a short list, the same order can come back, and that is correct behaviour rather than a bug.

Good to know

• Works offline once loaded, including on flights and in locked-down networks.
• No file size limit beyond your device's own memory.
• Free to use, with no account and no usage counter.
• Results are produced locally, so they are not logged or shared with anyone.

Questions