How list comparison works
Compare two lists by membership: which distinct values are only in A, only in B, or in both. Put one item on each line. Blank lines are ignored.
Start in three steps
- Add your lists
Paste one item per line, or import a file into List A and List B.
- Compare
Check the matching options, then choose Compare lists.
- Use your results
Choose Only in A, Only in B or In both. Copy the values or download a file.
Already comparing lists? Return to your original tool tab to keep working.
A worked example
Use Try example → Load example on the tool. List A contains 00123, 123, SKU-A, SKU-A on separate lines. List B contains 123, SKU-B.
With Trim outer whitespace on and Ignore case off:
| Result | Original values |
|---|---|
| Only in A | 00123 and SKU-A |
| Only in B | SKU-B |
| In both | 123 |
A has 4 valid input lines, 3 distinct values, and 1 duplicate extra row. The SKU-A group retains Input A, lines 3 and 4. It appears once in the output. This is not quantity reconciliation.
What the rules change
Trim removes outer spaces and the defined whitespace characters for matching only. Original values remain unchanged in results. Blank lines use that same rule even when trim is off.
Turn on Ignore case to match uppercase and lowercase versions of a word: Apple and apple will match. Your results keep the original spelling. Accents and other characters still matter: café and cafe, or ß and SS, remain different. Leading zeros and punctuation are kept. Text that looks identical can still differ because of hidden characters.
Technical details: matching, whitespace and line rules
Ignore case uses JavaScript toLowerCase(). Unicode is not normalized. Text U+FEFF and zero-width characters are preserved.
Outer whitespace: U+0009, U+000B, U+000C, U+0020, U+00A0, U+1680, U+2000–U+200A, U+2028, U+2029, U+202F, U+205F, U+3000. CRLF, CR and LF separate physical lines. One terminal newline does not create an extra placeholder line. Other trailing blank lines still count.
Original values and source lines
Each result represents the first original value in its group. In both uses A's value and A's order. Expand a result to inspect all matching variants and source lines from either input. File imports retain CSV record/column or XLSX worksheet/cell references. Edit as text clears these references. Pasted values use current input line numbers.
Copy, download and changes
Copy and TXT download include all values in the selected category, including those beyond the 100-item desktop or 50-item phone preview page. Outputs have one value per line and no header or added final newline. TXT is UTF-8 without an added encoding BOM.
Editing input, changing rules, swapping lists, or cancelling makes previous results unusable for export until you compare again. Both empty lists need input; a single non-empty list can be compared normally.
Limits
Each list can contain up to 100,000 lines, including blank lines, and about 5.2 MB of text. Both limits apply. Import UTF-8 TXT/CSV or ordinary unencrypted XLSX, one selected column per list. The exact size limit is 5,242,880 bytes. Tabs trigger a choice to cancel or keep each whole line; commas stay literal unless you explicitly use Clean up. The tool cannot establish identity, explain missing entries, or restore data that a spreadsheet already changed.
Clean up, sort and take the full result
Use Clean up beside either input for literal find/replace, quote removal, lowercase or splitting on a chosen delimiter. A comma in pasted text stays part of one value until you explicitly split it. Review the complete candidate's counts and first ten changes, then apply once. Both-list changes commit together; Undo restores the most recent cleanup and its sources.
Regular expressions are under Advanced. Global replacement is always on; i, m, s and u are optional. Text escapes decode only \n, \r, \t and \\ in the written fields. Regex source and inserted captures are never decoded as text escapes. Ordinary replacement treats dollar signs literally; regex templates use JavaScript capture, match, prefix and suffix substitutions. Failed or over-budget cleanup keeps the inputs and previous results.
All unique values in A/B includes shared values. Sorting applies to the complete result, before the 100-item desktop or 50-item phone page. Ignore case changes matching only. Names stay in this tab and never enter filenames. Original order remains the default.
Summary & export keeps the same results without rendering value lists. You can copy or download directly in this mode. Small prepared groups copy in one click; a larger group may first show Ready — Copy. If access is denied, the complete text and a download fallback remain available.
Only one file prepares at a time. An existing file remains available until a replacement succeeds, you release it, or inputs, rules, names or sorting change. Save file remains available beyond 60 seconds. A triggered download does not establish that your device saved it; check your browser's downloads or Files app.
Instagram lists
Follow the Instagram export comparison guide: file selection, examples and result checks →
See which accounts appear in both your Following and Followers lists, and which appear in only one. Choose HTML when downloading your Instagram information, then unzip the download. Add following.html (people you follow) to List A and choose Following. Add followers_1.html (people who follow you) to List B and choose Followers. If you also have followers_2.html or more numbered files, select all follower files together. Check the preview and choose Apply usernames for each list, then compare.
You can also paste usernames or Instagram profile links, one per line. Links are converted to usernames, and you can check the original links in your results. If pasted text contains entries the tool cannot recognize, review them before choosing whether to leave them out. If an HTML file cannot be read, try pasting usernames or profile links instead. ZIP and JSON files cannot be opened here.
With Following in A and Followers in B, Only in A shows accounts absent from the followers export, Only in B shows followers absent from the following export, and In both shows mutual follows in those files. Choose exports covering the same time period; their contents may differ from the current Instagram app.
Your files stay on your device and are not changed. You do not need to sign in to Instagram. Each list can contain up to 100,000 entries; HTML files selected together must total no more than about 5.2 MB. Large files may take longer on your phone. Results reflect the files you provide: a missing name does not necessarily mean someone unfollowed you.
Import a CSV or Excel column
Choose TXT / CSV / Excel beside each list. For XLSX, select a worksheet, then choose one column. Review First row contains headers, the first 10 values, and the full row count. Advanced options let you set a starting row and CSV delimiter. Choose Import values to replace that list; cancelling keeps it unchanged. To compare two columns from the same workbook, select that file separately for A and B.
Excel values are read as formatted text from the saved file. Formatting can affect comparisons. Hidden and filtered-out rows are included. Saved formula results require confirmation and may be out of date; formulas are never calculated. A selected column with missing formula results, errors, merged data cells, or internal line breaks cannot be imported. Text identifiers retain their digits, but this tool cannot recover digits already lost in Excel.
Expand results to inspect CSV record and column numbers or XLSX worksheet and cell addresses. Imported columns stay read-only. Change selection reopens the preview; Edit as text removes original file references and uses input line numbers.
Choose an output
Download Excel (.xlsx) creates a new workbook with three worksheets: Only in A, Only in B, and In both. Each contains a Value column with all compared values stored as text. Empty groups retain the header. It never changes the original workbook or includes other source columns.
Copy values, Download CSV, and Download TXT use the complete current result group, including values beyond the 100-item desktop or 50-item phone page. CSV includes a Value header, UTF-8 BOM and CRLF line endings. TXT and copying have no header and preserve the original result text. All input methods support every output format.
For IDs and long numbers, use Excel (.xlsx). CSV readers may change them. Formula-like CSV fields receive a protective apostrophe only after a disclosed confirmation; cancelling produces no file. That apostrophe remains data if you import the CSV again. TXT and clipboard output keep the original values; spreadsheet apps may interpret formulas or split tabs. Prefer XLSX for a text-preserving round trip.
Download starts in your browser; use Save file if a second click is needed. Check your browser's downloads or Files app: a triggered download does not prove it was saved or opened. Changes to inputs, rules, names or sorting invalidate old downloads.
File limits
Each file and extracted list is limited to about 5.2 MB and each list to 100,000 data rows, including blanks and excluding a selected header. CSV must be UTF-8. Only ordinary unencrypted XLSX is supported, with at most 20 worksheets, 256 used columns per sheet and 500,000 populated cells per sheet. Expanded ZIP data is limited to about 52.4 MB total, about 21 MB per part and 2,000 parts. Oversized data is rejected rather than truncated.
Imports stop after 10 seconds; exports stop after 15 seconds or an output limit of about 33.6 MB. Excel text cells are limited to 32,767 UTF-16 units; unsupported control characters are rejected. TXT or CSV remains available where its format supports the text. No original file is overwritten, no other columns are exported, and no complete-row matching is performed.
Try a sample you can check
The 9 October 2026 synthetic test by worktoolmap.com returned 3 / 2 / 4 distinct values in Only in A / Only in B / In both with trim on and case sensitivity on. The larger sample exported 125 / 125 / 125 values; every group was copied and its TXT, CSV and XLSX download reread.
For the base CSVs, enable the header option and select ID, the second column. For base.xlsx choose AInputs for A, BInputs for B and ID (column B). Expand 00123 to see CSV record 2, column 2 or AInputs, cell B2. Compare again after changing an input or a rule. These are text-cell samples, not evidence about numeric-cell recovery or formulas.
Download base workbook · Inputs, expected results and export checks (new tab)
Choose between an online list tool and an Excel workflow (new tab).