How is this different from the string category's String Line Filter?

String Line Filter always splits on "\n" and only supports plain substring containment matching, with an invert option. List Filter supports a configurable separator (newline, comma, or custom delimiter) and five match conditions (starts with, ends with, contains, regex, and minimum length), making it the more general-purpose tool for non-newline-delimited lists.

What does the invert option do?

It flips the result to keep everything that does NOT match the condition, instead of everything that does, without needing to rewrite your condition.

What does Minimum Length filter on?

Each item's character length (via `.length`); items at or above the minimum you set are kept (or excluded, if inverted).

What happens if nothing matches?

The output is an empty string; that's a valid, non-error result, since it simply means no items satisfied the condition.

List Filter - Keep Items Matching a Condition

Overview

Introduction

Filtering a list down to only the items that satisfy a condition, like a prefix, suffix, or minimum length, is a common cleanup and analysis task.

List Filter offers five match conditions and a configurable separator, plus an invert option, so one tool covers most "keep only" and "keep everything except" scenarios for delimited lists.

What Is List Filter?

A general-purpose conditional filter for delimited lists: choose a condition (starts with, ends with, contains, regex, or minimum length) and List Filter keeps only the items satisfying it.

The invert toggle flips the logic to keep only items that fail the condition instead, without needing a second tool.

How List Filter Works

The input is split into items using the selected separator, then each item is tested against the chosen condition and its pattern (or minimum length value).

Items passing the test are kept (or, with invert on, items failing the test are kept instead), and the surviving items are rejoined using the selected separator.

When To Use List Filter

Use it to keep only items starting or ending with a particular prefix or suffix, like filenames sharing an extension or IDs sharing a prefix.

It's also useful for length-based cleanup, for example stripping out overly short placeholder entries from a dataset.

Often used alongside String Line Filter, List Item Deleter and List Item Finder.

Features

Advantages

Five distinct match conditions cover most common filtering needs in one tool.
The invert toggle avoids needing to write a negated regex or a second pass.
Works on any configurable separator, unlike newline-only line filters.

Limitations

Regex mode uses default JavaScript regex flags; build in case-insensitivity yourself if needed.
Only one condition can be applied at a time; combining multiple conditions requires chaining the tool's output back into itself.

Examples

Starts With filter

Input

apple
banana
apricot (startsWith: "ap")

Output

apple
apricot

Only items beginning with "ap" are kept.

Minimum Length filter with invert

Input

a,bb,ccc (comma separator, minLength: 2, invert on)

Output

With invert on, only items shorter than the 2-character minimum are kept, the opposite of the normal minimum-length behavior.

Best Practices & Notes

Best Practices

Use the invert toggle instead of trying to write a negated regex pattern, it's simpler and less error-prone.
Chain multiple List Filter passes together (feed the output back in as input) to apply more than one condition.

Developer Notes

Each condition maps to a small predicate (`String.prototype.startsWith`, `.endsWith`, `.includes`, a compiled `RegExp.test`, or a `.length` comparison), applied via `Array.prototype.filter()` with the predicate's result optionally negated when `invert` is true.

List Filter Use Cases

Keeping only filenames with a specific extension pasted from a directory listing
Filtering a list of IDs down to those sharing a known prefix
Removing overly short or placeholder entries by minimum length

Common Mistakes

Forgetting the invert toggle exists and manually trying to write a negated regex pattern instead.
Expecting Minimum Length to trim whitespace before measuring; it measures the raw item length exactly as split.

Tips

If you need newline-only filtering with a simple contains/invert toggle, String Line Filter is a lighter-weight option for that specific case.
Combine Contains mode with invert to quickly strip out every item mentioning an unwanted term.

List Filter