Email Permutator

A static web app that generates ranked email-address guesses from a CSV of leads. All processing happens in your browser — no data is ever sent to a server.

Quick start

Open index.html directly in any modern browser (Chrome, Firefox, Edge, Safari).

1. Upload a CSV file of leads.
2. Verify the auto-detected column mapping (adjust dropdowns if needed).
3. Set your options (SMB mode, Top N, layout).
4. Click Process & Download CSV.

Input CSV

Your file needs at least a first-name column and a website/domain column. Column headers are matched case-insensitively and trimmed.

Field	Accepted header names
First name	first name, first_name, firstname, fname, first, given name
Last name	last name, last_name, lastname, lname, last, surname, family name
Company	company name, company_name, company, organization, organisation, account name
Website	website, company website, domain, url, web, company domain, site

See examples/sample_leads.csv for a sample input file.

Options

Option	Default	Description
SMB mode	ON	Reorders format patterns to put first-name-first variants at the top — common for small/medium businesses
Top N formats	4	How many format patterns to generate per lead (1–10)
Output layout	Long	long: one row per email guess; wide: one row per lead with email_1…email_N columns

Email format patterns

Rank (default)	Format	Example — john / smith
1	first.last	john.smith@
2	first	john@
3	flast	jsmith@
4	firstlast	johnsmith@
5	f.last	j.smith@
6	firstl	johns@
7	first_last	john_smith@
8	last	smith@
9	last.first	smith.john@
10	lastf	smithj@

SMB mode order: first, first.last, firstlast, flast, f.last, firstl, first_last, last, last.first, lastf

Name cleaning

• NFKD-normalised, accent-stripped, lowercased, only a-z kept.
• Split on spaces and hyphens.
• Common prefixes (dr, mr, mrs, ms, miss, prof) and suffixes (jr, sr, ii–iv, phd, md, cpa, esq, mba, dds, pe) are dropped.
• Multi-part names produce two variants (joined + alternate) to multiply coverage:
  • First name — alternate = first token (Mary Ann → maryann, mary).
  • Last name — alternate = first token, except when the first token is a particle (van, von, de, der, del, la, le, di, da, st) or ≤ 3 characters, in which case the alternate is the last token (van der Berg → vanderberg, berg; García-López → garcialopez, garcia).

Domain rules

• If the value contains @, the part after it is used.
• Subdomains are reduced to the root domain (shop.acme.com → acme.com).
• Multi-part TLDs are respected: co.uk, com.au, co.nz, co.in, com.br, co.za, com.mx, co.jp, com.sg, com.pk, org.uk, ac.uk, gov.uk, net.au, org.au.
• Leads with a free / social domain (Gmail, Yahoo, Hotmail, Outlook, AOL, iCloud, Live, MSN, LinkedIn, Facebook) produce no emails; the note column explains why.
• Missing domain or missing first name are similarly flagged in note.

Running the tests

node test.js

Requires Node.js 18+ (uses node:assert and URL).

Files

index.html              — the app (open directly in a browser)
permutator.js           — core logic; no DOM code; testable in Node.js
test.js                 — unit tests (node test.js)
examples/
  sample_leads.csv      — sample input CSV
README.md