# Merge Duplicates in a CSV or Excel File | Dedupely > Upload a CSV file to Dedupely, find duplicate rows and merge them before the data ever reaches your CRM. Works for lists from Excel or Google Sheets saved as CSV. - URL: https://dedupe.ly/knowledge-base/merge-duplicates-in-spreadsheets - Section: knowledge-base - Site index: https://dedupe.ly/llms.txt - Any page: append `.md` to its URL for this plain-text form --- ## Merge duplicates in spreadsheets By [Gaby Salinas](https://www.linkedin.com/in/gbyslns) Updated October 28, 2026 Upload your spreadsheets to Dedupely, merge the duplicate rows, and download a clean file. Dedupely can dedupe spreadsheets as well as CRMs. Upload a CSV file, find and merge its duplicates with the same tools you'd use on CRM records, and export a clean CSV, for example before importing an event list into your CRM. Unlimited spreadsheet uploads are included in every Dedupely plan and the 7-day free trial, and spreadsheet records don't count toward your plan's record limit. ### Before you start - **Save your file as CSV.** Dedupely accepts CSV files. If your list is in Excel or Google Sheets, save or download it as CSV first. - **Add a header row.** The first row must have column names, so Dedupely can turn your columns into fields. - **Check the limits** below. ### Spreadsheet limits | Limit | Value | | --- | --- | | Total size | 100 MB | | Files per upload | 10 | | Rows | 1,000,000 | | Columns | 50 | | Characters per cell | 350 | | Values per multi-value field | 175 | | Field name or label | 100 characters | | CSV instance name | 50 characters | | Size per line | 4 MB | ### One file or several - **Separate CSV instances:** upload each file as its own CSV instance to keep your lists apart. - **One combined CSV instance:** upload several files into one CSV instance, or add more files later. When you combine files, make sure the column headers are spelled the same in every file (e.g. "First Name", "Email", "Company"), so Dedupely puts them in the same fields. ### How to upload a spreadsheet Added July 9, 2026 #### When you sign up - After creating your account, go to the bottom of the **Connect a CRM to Get Started** screen. - Under **Other Data Sources**, click **Upload** on the **CSV** tile. - Upload your file(s), name your CSV instance, and confirm. #### From an account with a CRM connected You don't need a CRM to dedupe spreadsheets. - Click the **CRM** icon in the left menu. - Click **+ Add New CRM or CSV** at the bottom of the list. - Under **Other Data Sources**, select **CSV** and click **Upload**. - Choose your file(s) and name your CSV instance. #### From an existing CSV instance - **New, separate CSV instance:** click the CSV icon in the left menu and select **+ Add New CRM or CSV**. - **More files in the same CSV instance:** click **Edit CSV Settings** (the gear icon in the left menu), then **Upload More Files** in the **General** tab. ### How to dedupe and export - Create a Duplicate Search for your CSV instance, just like for a CRM object. See [How to Find Duplicates](https://dedupe.ly/knowledge-base/how-to-find-duplicates). - Merge the duplicates. See [How to Merge Duplicates](https://dedupe.ly/knowledge-base/how-to-merge-duplicates). - In **Edit CSV Settings** → **General**, click **Create Export** and choose the fields to include. ### CSV settings #### General - **Details:** your total number of records and fields. - **Create Export:** download a clean CSV, with the fields you choose. You can create as many exports as you need. - **Upload More Files:** add spreadsheets to this CSV instance at any time, e.g. a new event list. - **Remove:** permanently delete the CSV instance and its data from Dedupely. #### Fields - **Type:** how Dedupely reads the column. Spreadsheet columns import as text. - **Multi-value:** check this for columns with more than one value, like several email addresses. Merge Rules can then **Append** those values instead of overwriting them. #### Exports - **Export History:** every export you've created for this CSV instance. ### What happens next - **Your file is ready to dedupe** once it's uploaded. Create a Duplicate Search to find duplicates. - **Merges stay inside Dedupely.** Merging a spreadsheet doesn't change anything in your CRM. Use **Create Export** to download the clean file. - **Your plan isn't affected.** Spreadsheet records don't count toward your record limit. ### Troubleshooting **My file won't upload.** Check that it's a CSV file with a header row, and within the limits above (100 MB, 1,000,000 rows, 50 columns, 10 files per upload). If you have an Excel file, save it as CSV first. **Columns from two files didn't combine.** Their headers are spelled differently. Rename the headers so they match, then upload again. **My file has very long values.** Cells can hold up to 350 characters, and multi-value fields up to 175 values. Shorten longer values before uploading. **Merging overwrote one of several emails.** Mark the column as **Multi-value** in the **Fields** tab, then set it to **Append** in [Merge Rules](https://dedupe.ly/knowledge-base/merge-rules). ### FAQs about deduping spreadsheets - **Can I upload Excel files?** Save them as CSV first. Dedupely accepts CSV files, including ones exported from Excel and Google Sheets. - **Do my files need a header row?** Yes. The first row must have the column names. - **What happens if my files have different column headers?** Matching headers are combined into one field. Different headers become separate fields. - **Do spreadsheets count toward my plan's record limit?** No. Spreadsheet uploads are unlimited and don't count toward your record limit. - **Do I need a CRM to dedupe spreadsheets?** No. - **Why use Dedupely instead of cleaning spreadsheets by hand?** You decide what counts as a duplicate and which values win, reject false matches, and can automate the whole thing, instead of checking rows one by one. ### Next up [How to Find Duplicates Create a Duplicate Search for your spreadsheet and choose what counts as a duplicate.](https://dedupe.ly/knowledge-base/how-to-find-duplicates) ### Changelog - July 9, 2026 #### CSV upload rebuilt CSV upload has a new flow and processes files faster. A file is searchable for matches as soon as it is imported, and matches exports carry each record's ID. [Every change in the knowledge base](https://dedupe.ly/knowledge-base#changelog) ### Still stuck? Our team helps on every plan and during the free trial, by chat, email or Zoom. - Need help? [Talk to support](https://dedupe.ly/contact) - Questions about plans? [Book a Zoom with sales](https://meetings.dedupe.ly/meetings/gaby-salinas/talk-to-sales) - Reading this with a model? [Read this page as Markdown](https://dedupe.ly/knowledge-base/merge-duplicates-in-spreadsheets.md) - Feeding it the whole site? [Read llms.txt](https://dedupe.ly/llms.txt) Behind the article ### Gaby Salinas Marketing Assistant at Dedupely Gaby Salinas came to CRM data from marketing and advertising, so she looks at duplicates from two sides: the match and merge logic behind them, and what they do to the people using the CRM, like the rep who calls a customer twice, the admin who gets blamed and the cleanup nobody wants to start. As Marketing Assistant at Dedupely, she follows how RevOps teams, end users, consultants and technical teams actually work with their data: the records they stop trusting, the workarounds they build and the moment they finally decide to clean up. What she finds shapes most of what Dedupely publishes. [Connect with Gaby on LinkedIn](https://www.linkedin.com/in/gbyslns) ### Get started for free 20 free trial merges and as much free support as you need to get your duplicates under control. [Talk to sales](https://meetings.dedupe.ly/meetings/gaby-salinas/talk-to-sales)[Try for free](https://v2.app.dedupe.ly/signup) [Or sign up with Google](https://v2.app.dedupe.ly/signup/google) Running CRM cleanup for clients? [See the Partner Program](https://dedupe.ly/become-a-partner) Skip to content