--- title: "Tool to compare two lists" description: "Compare two lists of emails or anything else: see what’s only in the first, only in the second and in both, then copy or download each. Free, no sign-up." canonical: https://www.acquisity.ai/tools/compare-two-lists --- # Tool to compare two lists > Compare two lists of emails or anything else: see what’s only in the first, only in the second and in both, then copy or download each. Free, no sign-up. Paste or choose two lists. We show what’s only in the first, only in the second and in both, and you can copy or download each one. It runs in your browser, so your lists never leave your computer. Use the tool in a browser at [/tools/compare-two-lists](https://www.acquisity.ai/tools/compare-two-lists). It is free and needs no sign-up. ## How the lists are compared - Each line is one entry. A valid email address, written like name@company.com with letters A to Z, digits and the usual symbols, matches whatever its capitals and the spaces around it, so Sam@Acme.com and sam@acme.com are the same. - Any other line matches only as typed, once the spaces at its ends are trimmed, so Acme Inc and acme inc are different. - In a CSV, a row with a name, a note or other columns beside one valid email address is compared by that address, so a row with a name and an email matches the same email on its own. Only valid addresses count in such a row: a handle like @samlee, a link, a note or a mistyped second address beside it doesn’t. A name and address like Sam Lee counts as that address. A line of nothing but addresses, separated by commas or semicolons as in a To line copied from an email, gives one entry for each, names written Last, First included. If one of them isn’t a valid address, like josé@acme.com or Dana , the whole line is compared as typed. Any other row, with no valid address or two different valid ones beside other text, is compared as a whole row. - An entry that appears twice in one list is listed once, and the result says how many repeats it set aside. - In a CSV with several columns, a first row that heads the email column with a common name, like Email, Invitee Email, user_email or Your email address, is skipped as a header when the rows below hold valid email addresses in that column. In a one-column list, only a line like Email, Work Email or Email (Work) is, and only when valid addresses follow it. - Nothing is fixed or guessed. sam @acme.com, sam [at] acme.com and josé@acme.com (letters outside A to Z) aren’t valid addresses, so a line of one of them is compared as typed, capitals included. To tidy each list first and flag likely typos such as gmial.com, run each one through the [email list cleaner](https://www.acquisity.ai/tools/email-list-cleaner). ## Check a new list before you send Put the new list first and the people you’ve already emailed, or must not email, second. Only in the first list is what’s left to send to, and In both lists shows the addresses you’d be emailing again. A line that can’t be read as a single address or a list of them is compared as typed, and the result says how many there were, so check those by eye. ## What it doesn’t do It doesn’t match close spellings or pick a column for you: each side is one list. It runs in your browser, and your lists aren’t uploaded or saved. ## Questions ### How do I compare two lists for duplicates? Paste one list in each box and choose Compare lists. In both lists shows every entry the two share, each once. ### How do I remove from one list everything that’s in another? Put the list you want to keep first and the list to take out second. Only in the first list is what’s left. Copy it, or download it as a CSV. ### Does it match email addresses written with different capitals? Yes, for valid email addresses: they match whatever their capitals and the spaces around them. Other lines match exactly as typed, once trimmed, and that includes a line with letters outside A to Z, like josé@acme.com. ### Can I compare two CSV or Excel files? Yes. Choose a CSV file for each list, or copy the cells from Excel or Google Sheets and paste them. A row with a name, a note or other columns beside one valid email address is compared by that address. A row of nothing but addresses gives one entry for each, or is compared as a whole if one of them isn’t valid. Any other row is compared as a whole. Excel files themselves (.xlsx) can’t be read directly, so save them as CSV first. ### Are my lists uploaded or stored? No. Both lists are read and compared in your browser, and they’re never sent to us or saved. ### How big can the lists be? Up to 10 MB of text each, which is well over 100,000 lines. Past that, we compare the first 10 MB of that list, up to the last whole line, and say so. ## Checking a new list against people you’ve already emailed? On paid plans, when you upload leads to a campaign, Acquisity skips repeats, invalid addresses, people on your blocklist and people already in another campaign you haven’t archived, and shows you what it skipped. [Cold Email Agent](https://www.acquisity.ai/agents/cold-email). --- Web page: https://www.acquisity.ai/tools/compare-two-lists Site index for agents: https://www.acquisity.ai/llms.txt