Free tool
Customer list hasher for Google and Meta Ads.
Turn your customers' emails and phone numbers into the scrambled SHA-256 codes that Google Ads Customer Match and Meta Custom Audiences require. Each platform wants the data formatted differently. This tool builds both. Every step runs locally inside your own browser, so your customers' emails and phone numbers never leave your device and are never sent to our servers or to anyone else.
What this does, in plain words
To show ads to people who are already your customers, Google and Meta let you upload your customer list. But you must never upload real email addresses or phone numbers. So each one is turned into a secret code that can never be turned back into the original. This is called a hash. For example, [email protected] becomes 831f6494.... The same email always makes the same code, so Google and Meta can still match your customers without ever seeing their real details. This tool makes those codes for you, right here on your own computer.
- Add list
- Configure
- Export
The tool auto-detects your email and phone columns, and assumes your numbers already include their country code.
Add your customer list
How your file should look. Use one of these two simple layouts:
- One column. A list of just emails, or just mobile numbers, one per row. Keep one column to one type.
- Two columns. An email column and a mobile column, one person per row. A header row like
email,mobileis fine.
Extra columns like names are ignored. Download a sample CSV to try it.
Drop a .csv, .xlsx or .xls file here, or click to browse.
What do you want to scramble?
Mobile number settings
Google wants the phone code made with a plus sign, like +6591234567. Meta wants digits only, like 6591234567. The tool makes both, so the email code stays the same in each file and only the phone part changes.
Waiting for your list.
Download your safe file
Add a list and press Hash my list. Your ready-to-upload files will show up here, holding only the secret codes.
Google Ads format
Phone code made with the + sign. This is what Google Ads Customer Match asks for.
Meta Ads format
Phone code made with digits only, no +. This is what Meta Custom Audiences asks for.
Using another platform? The email code is the same everywhere, so an email-only file works on most platforms that take hashed lists, like Microsoft Advertising, TikTok, LinkedIn, Snapchat, X, Reddit, Pinterest, and Amazon Ads. Phone rules can be different, so check that platform's own guide before you upload a phone file.
| # | Email SHA-256 | Phone | Phone SHA-256 (Google) | Phone SHA-256 (Meta) |
|---|
This preview shows the first 200 rows so you can check it. Your downloaded file has every row, and only the codes.
How it works
How does hashing a customer list for Google and Meta Ads work?
It only goes one way
A hash turns any text into a code of 64 letters and numbers. You can never run it backwards to get the email or number back. Google and Meta make the same codes from their own users, then match the codes.
It all stays on your computer
The codes are made by your browser itself, the same kind of maths it already uses for secure (padlock) websites. The page never sends your list anywhere. The only extra thing it might load is a small helper for reading Excel files, and even that never sees your contacts.
Making the codes keeps the data safe while you upload it. If you want the audience strategy that makes Customer Match and Custom Audiences actually pay back, that is the work we do on paid social and AI performance marketing, across Google Ads and Meta Ads.
Questions
Customer list hashing, answered simply.
Does any of my data get sent to leapbuzz or uploaded anywhere?
No. Everything happens on your own computer, inside your web browser. Your customer list is never sent to leapbuzz, and never sent to anyone else. We never see it. The easiest way to check: once the page has loaded, turn off your wifi. The tool still works, because it does not need the internet.
What is a hash?
A hash is a secret code made from a piece of text. The same text always makes the same code, but you can never turn the code back into the original text. Google and Meta turn their own users into the same kind of codes, then match the codes. That way they can find your customers without ever seeing a real email or phone number.
Why are there two files, one for Google and one for Meta?
Only the phone format is different. Google wants the phone number with a plus sign in front, like +6591234567. Meta wants just the digits, like 6591234567. The email code is exactly the same in both files. This tool makes both for you, so you just pick the one for the platform you are using.
Do my phone numbers need a country code?
Yes. Both Google and Meta need the country code to match phone numbers. If your numbers already have it, you are ready. If they are local numbers with no country code, choose your country in Step 2 and the tool adds it for you. The plus sign does not matter, the tool sorts that out.
What kind of file can I upload?
You can paste your list, or upload a CSV, XLSX, or XLS file. Paste and CSV work even with no internet. Your file can have one column (just emails, or just phone numbers) or two columns (email and mobile). The tool finds the right columns on its own and ignores extra ones like names.
Can I use this for TikTok, Microsoft, LinkedIn, or other platforms?
Often, yes. Most big ad platforms accept these hashed lists, and the email code is the same everywhere, so an email-only file usually works. Only the Google format (with the plus sign) and the Meta format (digits only) are built in and checked here. Other platforms like Microsoft Advertising, TikTok, LinkedIn, Snapchat, X, Reddit, Pinterest, and Amazon Ads also take hashed lists, but their phone rules can differ, so check that platform's own guide before you upload a phone file.
Is it really free?
Yes. It is free and there is no sign-up. We built it because our clients kept asking how to prepare their lists safely. If you want help turning matched audiences into results, just get in touch.
Matched the audience. Now make it pay back.
We run paid social and Google Ads for regulated and high-consideration brands across five markets. A senior practitioner will read your actual setup, no deck, no templates.
Talk to us