What counts as a match between the two lists?

Matches use the whole line as text. "apple" and "apples", "12" and "12.0", and "cafe" and "café" remain different. Trim spaces removes whitespace at each end; Case controls letter case. There is no fuzzy matching or numerical conversion.

What is the difference between Fold and Count?

Fold treats each different line as one entry however often it repeats. Count keeps the repeats and pairs them off. Here is the same pair of lists under both: list A holds a, a, b and list B holds a, c. With Fold you get In both: a. Only in A: b. Only in B: c. With Count you get In both: a, because B has only one a to pair with. Only in A: a, b, since A's second a has nothing to pair with. Only in B: c. In other words the shared group takes the smaller of the two counts and the difference groups carry the excess, so every line you pasted is accounted for exactly once. Fold is what a followers list or an email list needs. Count is what a stock take or an attendance sheet needs, where three of a part number is not the same as one.

Does the tool keep the order I pasted?

Results use the order distinct lines are first seen while List A is read before List B, without sorting. In both and Only in A follow A’s first-seen order. With Fold, Only in B follows B’s order. With Count, extra B copies of lines already seen in A can appear before B-only lines. In one but not both puts Only in A before Only in B; repeated copies stay together, and Case set to Ignore keeps the first spelling seen.

Are my lists uploaded anywhere?

The comparison runs in this browser without uploading the lists or requiring an account. Drafts and the three options are saved locally; Start over above the tool clears them. A list longer than 100,000 characters is compared in full but omitted from the local save. Browser storage restrictions can prevent a draft from being remembered.

How many lines can I compare?

Up to 200,000 lines in each list. Empty lines are dropped; with Trim spaces on, whitespace-only lines are dropped too. Larger inputs produce an error naming the list and its line count. Split them into smaller lists to continue. An empty box is valid: the other list appears under Only in A or Only in B.

How do I get everything that is in one list but not both?

That is the fourth group, In one but not both, sometimes called the symmetric difference. It is Only in A and Only in B stacked together, so it answers "what changed between these two lists" in one column. Every group has its own Copy button and its own Download, which writes that group as a plain text file, one line per entry, and Copy all writes all four groups under labelled headings with their counts. The rows on screen spell out the first twelve lines and count the rest, but Copy and Download always write every line.

Can I compare two columns from a spreadsheet?

Copy one column into List A and the other into List B, with one cell per line. Commas stay inside an item, so "Smith, John" remains one line. Paste only the values you want to compare; tab-separated rows with several cells are compared as whole lines. This page does not open workbooks or run Excel formulas.

Can I compare Instagram followers and following lists?

You can compare two plain-text username lists that you supply. Put Following in A and Followers in B; Only in A shows names in your following list that are absent from your follower list. Use one username per line and the same case and whitespace settings for both. This tool does not log in to Instagram, fetch account data or parse its export archives.

Can I compare ingredients, names or file lists?

Yes. Supply one ingredient, name, file name or path per line in each box. The results identify exact text shared or missing under your case and spacing settings. Similar ingredient names are not normalized, and no safety, price or product-quality comparison is made. File-name lists compare their text; this page does not read folders or compare file contents.

List Compare

Paste one item per line into List A and List B. In both, Only in A, Only in B and In one but not both appear together with counts. Choose whether to trim spaces, match case and fold or count duplicates, then copy or download a result.

List Aone item per line

List Bone item per line

Two empty boxes.

All four answers at onceYour order, never sortedBoth lists stay in this browserNo account, no sign-up

Trim spaces

Case

Duplicates

In both0 lines, lines that appear in list A and in list B
nothing in this group
Only in A0 lines, lines list B does not have
nothing in this group
Only in B0 lines, lines list A does not have
nothing in this group
In one but not both0 lines, everything missing from the other list
nothing in this group

Paste a list into each box. The four results appear as you type, and nothing leaves this tab.

Every line is one item, so an entry written "Smith, John" stays whole and only a line break starts the next one. Blank lines are dropped. Trim spaces decides whether the space around a line counts as part of it, Case decides whether "Apple" and "apple" are the same line, and Duplicates decides whether a line that repeats is one entry (Fold) or as many as it appears (Count).

Accuracy. Exact string comparison on the lines you paste, after the trim and case options you choose. Every list is returned in the order the lines were first seen, never sorted. In counting mode a line that repeats is counted, and the shared list takes the smaller of the two counts.

Common questions

What counts as a match between the two lists?: Matches use the whole line as text. "apple" and "apples", "12" and "12.0", and "cafe" and "café" remain different. Trim spaces removes whitespace at each end; Case controls letter case. There is no fuzzy matching or numerical conversion.
What is the difference between Fold and Count?: Fold treats each different line as one entry however often it repeats. Count keeps the repeats and pairs them off. Here is the same pair of lists under both: list A holds a, a, b and list B holds a, c. With Fold you get In both: a. Only in A: b. Only in B: c. With Count you get In both: a, because B has only one a to pair with. Only in A: a, b, since A's second a has nothing to pair with. Only in B: c. In other words the shared group takes the smaller of the two counts and the difference groups carry the excess, so every line you pasted is accounted for exactly once. Fold is what a followers list or an email list needs. Count is what a stock take or an attendance sheet needs, where three of a part number is not the same as one.
Does the tool keep the order I pasted?: Results use the order distinct lines are first seen while List A is read before List B, without sorting. In both and Only in A follow A’s first-seen order. With Fold, Only in B follows B’s order. With Count, extra B copies of lines already seen in A can appear before B-only lines. In one but not both puts Only in A before Only in B; repeated copies stay together, and Case set to Ignore keeps the first spelling seen.
Are my lists uploaded anywhere?: The comparison runs in this browser without uploading the lists or requiring an account. Drafts and the three options are saved locally; Start over above the tool clears them. A list longer than 100,000 characters is compared in full but omitted from the local save. Browser storage restrictions can prevent a draft from being remembered.
How many lines can I compare?: Up to 200,000 lines in each list. Empty lines are dropped; with Trim spaces on, whitespace-only lines are dropped too. Larger inputs produce an error naming the list and its line count. Split them into smaller lists to continue. An empty box is valid: the other list appears under Only in A or Only in B.
How do I get everything that is in one list but not both?: That is the fourth group, In one but not both, sometimes called the symmetric difference. It is Only in A and Only in B stacked together, so it answers "what changed between these two lists" in one column. Every group has its own Copy button and its own Download, which writes that group as a plain text file, one line per entry, and Copy all writes all four groups under labelled headings with their counts. The rows on screen spell out the first twelve lines and count the rest, but Copy and Download always write every line.
Can I compare two columns from a spreadsheet?: Copy one column into List A and the other into List B, with one cell per line. Commas stay inside an item, so "Smith, John" remains one line. Paste only the values you want to compare; tab-separated rows with several cells are compared as whole lines. This page does not open workbooks or run Excel formulas.
Can I compare Instagram followers and following lists?: You can compare two plain-text username lists that you supply. Put Following in A and Followers in B; Only in A shows names in your following list that are absent from your follower list. Use one username per line and the same case and whitespace settings for both. This tool does not log in to Instagram, fetch account data or parse its export archives.
Can I compare ingredients, names or file lists?: Yes. Supply one ingredient, name, file name or path per line in each box. The results identify exact text shared or missing under your case and spacing settings. Similar ingredient names are not normalized, and no safety, price or product-quality comparison is made. File-name lists compare their text; this page does not read folders or compare file contents.

Exact string comparison on the lines you paste, after the trim and case options you choose. Every list is returned in the order the lines were first seen, never sorted. In counting mode a line that repeats is counted, and the shared list takes the smaller of the two counts.