List Comparer

About List comparer

The list comparer takes two lists, one item per line, and sorts everything into buckets: items in both, items only in list A, items only in list B, and the symmetric difference of the two. It is a set comparison for people reconciling customer lists, checking what changed between exports or finding what one file has that another lacks.

How to use it

1. Paste the first list into List A and the second into List B, one item per line.
2. Set the switches: Case sensitive, Trim whitespace around each item, Ignore blank lines and Collapse repeats within each list.
3. Read the count badges, then use the tabs to view In both, Only in A, Only in B or Symmetric difference.
4. Copy the bucket you need, or click the swap button to exchange the two lists.

Case-insensitive comparison

A: apple, banana, Cherry, date
B: banana, cherry, fig

In both: banana, Cherry
Only in A: apple, date
Only in B: fig

When to use it

• Finding which subscribers appear in an old export but are missing from the new one.
• Checking which files, IDs or usernames two systems have in common.
• Working out what was added or removed between two versions of a keyword or URL list.
• Reconciling an invoice list against a payment list to see what remains unmatched.

Questions about List comparer

What is the symmetric difference?

It is every item that appears in exactly one list, meaning the items only in A followed by the items only in B. Items present in both lists are excluded.

Which spelling of an item is displayed when case is ignored?

The first spelling seen. In the example, Cherry in list A is shown in the In both bucket even though list B holds cherry in lowercase.

What does Collapse repeats within each list change?

With it on, an item listed several times counts once. With it off, each occurrence is reported separately and the counts reflect every line.

Does the order of lines matter?

Not for deciding which bucket an item falls into, only for how results are listed. Each bucket keeps the order in which its items first appear in your lists.

Related tools

• List randomizerEasily convert a list of given text into a randomized list.
• Reverse listReverse a list of given text lines.
• List alphabetizerSort a list of text lines in alphabetical order. Supports both ascending and descending modes.
• Line numbererAdd or remove line numbers with a configurable start, step and format.
• Text separatorSeparate text back and forth by new lines, commas, dots, etc.
• Email extractorExtract email addresses from any kind of text content.