CSV Dedupe: Remove Duplicate CSV Rows Online for Free
CSV Dedupe finds and removes repeated rows from CSV data. Match rows across all columns or a selected subset by index, then choose whether to keep the first or last occurrence. You can optionally compare values case-insensitively or after trimming. Removed rows are listed for review, and you can copy or download the unique set.
CSV Dedupe is a browser-based tool for finding and removing duplicate rows from CSV data. It lets you compare every column or select a subset of columns by index, then choose which matching occurrence to keep. The result is a unique set of rows, while removed rows are listed so you can review what changed before copying or downloading the output.
To use the CSV Dedupe, paste or enter your CSV input and adjust the matching options. Matching can be case-insensitive, and you can optionally trim values before comparing them. Choosing all columns makes a row match based on its full set of values; choosing selected indexes bases the match on only those columns. The keep-first or keep-last setting controls which matching row remains.
CSV is a text-based format commonly used to represent rows and columns, so repeated records can occur when data is combined or exported more than once. CSV Dedupe does not change the data into another format: it filters repeated rows according to your chosen comparison rule. This helps when you need a unique CSV while retaining its column-based structure.
Processing runs entirely in your browser; your input is not sent to a server. The tool has no server dependency, so after the page loads it continues to work offline. You can deduplicate data without installing anything locally or sending internal content to a third-party service. Developers and DevOps engineers can use it for routine cleanup on the machine and browser already available to them.
Step 1: Paste or enter your CSV content. This gives the tool the rows to check for duplicates.
Step 2: Choose how to match rows. Compare all columns or select a subset of columns by index.
Step 3: Set which matching row to keep. Choose the first or last occurrence, and optionally match case-insensitively or after trimming.
Step 4: Review the removed rows, then copy the result or download the unique set.
Use case: Clean up a CSV export that contains repeated records before using it in another workflow. Choose whether a duplicate is defined by the full row or selected column indexes.
Use case: Deduplicate data combined from multiple CSV files. Keep the first or last matching occurrence to control which row remains.
Use case: Prepare a unique list based on specific fields rather than every column. Matching by selected indexes helps when other columns differ but should not determine whether rows are duplicates.
Use case: Standardize comparisons when values differ only by letter case or surrounding whitespace. Enable case-insensitive matching or trimming to apply those comparison rules.
Use case: Audit a cleanup before using the output. Review the listed removed rows to see which records were excluded.
Use case: Handle a routine CSV deduplication task in the browser without installing anything locally. This is useful when you are working on a machine without your usual tools.