✓ TestedWorks with CSV, Excel, Google Sheets → JSON-LD Schema
By dataclean.to team · 2026-02-12
Notion databases used as CRMs, project trackers, and knowledge bases accumulate duplicates when multiple team members add pages without checking existing entries, when database templates are instantiated with pre-filled data, and when Notion API integrations push records that already exist. A content calendar database might have 'Q1 Blog Post Plan' entered by three editors who each assumed they were creating the original. dataclean.to scans your Notion CSV exports to find duplicate rows by comparing page titles, properties, and content fields.
The Problem
Notion databases lack uniqueness constraints and do not warn users when creating a page with the same title as an existing entry. In a team of 10 people using a shared contacts database, duplicate entries accumulate rapidly because there is no automatic check for existing records. Relation properties that link databases together compound the problem: a duplicate company page means deals linked to one copy are invisible when viewing the other. Rollup calculations across these relations produce incorrect totals. Notion's API integrations from tools like Zapier add records without deduplication, creating entries for contacts or tasks that already exist. The lack of a built-in deduplication feature means these duplicates persist until someone manually reviews the entire database. Notion API documentation
How to Fix It
1
Export your Notion database
Open the Notion database, click the three-dot menu, and select Export as CSV. For linked databases, export each database separately. Ensure all properties (columns) are visible before exporting so they are included in the CSV.
2
Upload the CSV to dataclean.to
Upload the exported database. The tool analyzes page titles and property values to identify duplicate rows. Fuzzy matching catches entries like 'Acme Corp' and 'Acme Corporation' that Notion treats as completely different pages.
3
Review duplicate page clusters
Examine groups of pages flagged as duplicates. The tool shows property differences between entries, including different relation links, status values, and text content, so you can determine which page is the canonical version.
4
Merge duplicate pages
Consolidate duplicate database rows into single entries. Properties from secondary duplicates are merged into the primary page, including relation links, tags, and any unique content not present in the primary entry.
5
Export and apply changes
Download the deduplicated CSV. Use the results to manually clean your Notion database by deleting duplicate pages and updating the surviving entries with merged data. Redirect any relation links from deleted pages to the canonical entry.
Frequently Asked Questions
Can the tool handle Notion relation and rollup properties?
Relation properties export as comma-separated page titles in CSV format. The tool matches these as text values for deduplication. After cleaning, you will need to update relation links in Notion to point to the surviving pages instead of deleted duplicates.
How are Notion pages with rich content handled?
Notion exports only database properties (columns) to CSV, not the full page content. Deduplication is based on property values like title, tags, dates, and status. For pages with extensive content, review the flagged duplicates in Notion to compare their body content before merging.
Does it work with Notion databases used as CRMs?
Yes. CRM-style Notion databases with contacts, companies, and deals are a common use case. The tool matches contacts by name and email properties, companies by name, and deals by title and associated company, following the same patterns as dedicated CRM deduplication.
Example: Input → Output
name
email
phone
city
status
Alice Johnson
alice@example.com
+1-555-0101
New York
active
alice johnson
ALICE@EXAMPLE.COM
5550101
new york
Active
Red rows show common data quality issues. dataclean.to normalizes and generates JSON-LD automatically.