Lead List to Listmonk Converter
Transform any lead list or CRM export into official Listmonk subscriber CSV format. Auto-detects emails, merges first and last names, and preserves all custom columns inside valid JSON attributes — processed locally in your browser with zero uploads.
or drop files here
Accepts CSV, TSV, TXT, JSON · processed on your device, never uploaded
Advanced settings
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How to convert a lead list for Listmonk
- 1
Add your lead list
Drop in a CSV, TSV, TXT, or JSON file exported from HubSpot, Apollo, LinkedIn, Google Sheets, or Excel. Convert multiple lead files at once.
- 2
Auto-detect and map columns
The converter instantly identifies email and name fields, and bundles all remaining custom columns into Listmonk-compliant JSON attributes.
- 3
Download and import
Download your ready-to-import CSV and upload it directly in Listmonk under Subscribers → Import with zero formatting headaches.
Features
Smart column detection
Automatically detects email and name columns regardless of header variations, including separate first and last name columns.
JSON attributes preserved
Every custom column — phone, company, title, tags, or notes — is cleanly bundled into Listmonk’s double-escaped JSON attributes.
100% private & on-device
Your valuable customer and lead data never touches any server. All processing runs in memory on your computer.
Batch file conversion
Convert multiple campaign lists in a single batch. Download individual Listmonk CSVs or all results packaged in a ZIP.
Official Listmonk CSV format
Listmonk requires a standard three-column CSV structure: email (required), name (optional), and attributes (a valid JSON map of custom fields with double-escaped quotes per RFC 4180).
- email,name,attributes header format
- Valid JSON attributes with double-escaped CSV quotes
- Compatible with Listmonk UI and Import API
Supported lead export formats
Export leads from your favorite sales tool or spreadsheet. This converter accepts delimited tables and structured lead arrays.
- CSV (comma-separated), TSV (tab-separated), semicolon (Excel EU)
- Exports from Apollo, HubSpot, Salesforce, Hunter, PhantomBuster
- JSON lead exports and custom spreadsheet tables
Frequently asked questions
How does this converter format leads for Listmonk?
It scans your input file, identifies the email and name columns, and turns every other column (company, job title, phone, tags, location, custom IDs) into key-value pairs inside a valid JSON attributes column, formatted with RFC 4180 double-escaped quotes as required by Listmonk.
What if my file has separate First Name and Last Name columns?
The converter automatically detects both columns, combines them into the main Listmonk name field (e.g. “Jane Doe”), and also preserves the original first and last names in the attributes object so your email templates can use {{ .Subscriber.Attribs.first_name }}.
Are my contacts or lead lists uploaded to a server?
No. The conversion runs entirely inside your browser using JavaScript. No customer data, email addresses, or phone numbers are ever sent over the network or stored on any server.
How do I import the converted CSV into Listmonk?
In your Listmonk admin panel, go to Subscribers → Import, select the list(s) you want to add contacts to, upload your converted CSV, choose whether to overwrite existing contacts, and click Start import.
Which file types can I upload?
You can upload CSV (.csv), tab-separated (.tsv), text (.txt), and JSON (.json) files up to 20 files at once.
Want every tool, with zero uploads?
FreeConvert runs entirely in your browser. Pick a file, get a result — nothing ever leaves your device.
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