CSV row difference
Keep rows from CSV A whose selected key is missing from CSV B. Use one exact key, or a supplier + SKU pair when different suppliers reuse the same SKU.
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Single key: only an empty string is incomplete. A empty keys stay; B empty keys are ignored. Whitespace-only keys are exact values and can match.
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A · Rows to check
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B · Existing keys to exclude
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Each file: UTF-8, up to 2 MiB (2,097,152 bytes), 20,000 data rows and 200 columns. Headers required. No Excel workbooks. Choose each delimiter explicitly.
Choose the right matching rule
- Choose Single key for an identifier that is unique across both lists, or Supplier + SKU when SKU is unique only within a supplier. Select the delimiter for each file, then Read columns.
- Choose the matching column in each list. In Supplier + SKU, choose two different columns per list: supplier first, SKU second. Names and column order can differ; confirm the displayed mapping.
- Exclude matching rows, review the preview and warnings, then Download remaining CSV. Save your original files and review the download before importing it.
Matching is case-sensitive exact text. Leading zeroes and nonblank surrounding spaces matter: 001 differs from 1. No trimming of nonblank keys, number conversion, Unicode normalization or alias matching occurs. NULL and N/A are literal strings, not verified identities.
Two modes have different incomplete-key rules
Single key preserves A’s empty-string keys and ignores B’s empty-string keys. Whitespace-only keys are values that can match. Supplier + SKU treats either empty or whitespace-only part as incomplete: A’s row stays for review, B’s row is ignored. Switching mode clears previous column mappings and results.
For example, A has ACME/100 and BETA/100; B has only ACME/100. Supplier + SKU excludes ACME and keeps BETA. Matching only SKU excludes both. Both lists must use the same supplier identity system: ACME and Acme Ltd remain different, even if they refer to the same business.
Repeated complete keys in B are used by membership, not consumed by count. Every matching A row is excluded; all unmatched duplicates stay in order. Remaining row counts are not unique new products. This tool does not compare price or stock, update catalog fields, or produce a ready-to-import product list.
UTF-8 files, format and local limits
Each input supports up to 2 MiB (2,097,152 UTF-8 bytes), 20,000 data rows and 200 columns. CSV, TSV or text files must have nonempty unique headers and consistent row widths. Choose Comma, Semicolon or Tab separately for A and B. Quoted separators, doubled quotes, CRLF, LF, CR and quoted multiline cells are supported; blank records, NUL and malformed quotes are rejected. Excel/XLSX, UTF-16, legacy encodings, automatic delimiter detection and URL imports are not supported. Export CSV UTF-8 from your spreadsheet editor.
Long preview cells and column labels are shortened for readability; the table scrolls horizontally and vertically. Matching and downloaded CSV always use full original values. Unedited file A keeps its BOM, original header, delimiter, quoting and remaining original records in order. Editing or pasting uses the textarea’s line endings; byte preservation before a paste is not promised. Formula-like values are unchanged; spreadsheet software may interpret them as formulas.
File reads stop after 10 seconds; processing stops after 5 seconds. Errors preserve useful input and invite reselecting or reading columns again. Cancelling, editing, changing the delimiter or mode, clearing and leaving invalidate previous processing and downloads. Parsing and matching require browser Workers; there is no upload fallback. No task starts automatically.
To convert CSV into JSON, use CSV to JSON. To inspect exact line edits, use Text compare. Content does not transfer between tools; download or copy what you need before leaving.
Last reviewed: 2026-11-03