DievioEmail List Compare & Suppression Tool
Compare two email lists to find shared addresses, entries unique to each list and contacts to keep after suppressing list B. Export each group.
How to use this tool
- Paste your prospect list as A and your exclusion list as B.
- Compare the address sets.
- Export A-only to remove the supplied suppression addresses.
A worked example
Input
A: jane@example.com, alex@example.org B: alex@example.org
Output
Shared: alex@example.org A-only / not suppressed: jane@example.com
Download A-only excludes every supplied B address. It does not infer additional suppression rules.
What the result means
Use A-only when list B is your exclusion or suppression list. Shared entries appear in both sources; B-only is useful for investigating exclusions absent from the current prospect list.
Matching trims whitespace and normalizes the domain, while preserving local-part case. Invalid entries are reported. Suppression only matches supplied addresses.
Frequently asked questions
Which result should I use for suppression?
Put prospects in A and addresses to exclude in B. Copy unsuppressed emails or download A-only to get the addresses from A that do not appear in B. Shared and B-only groups have their own copy and export controls.
Are capital letters and duplicate entries normalized?
Whitespace is trimmed, duplicate entries are removed and domains are normalized. The local part before @ preserves its letter case, so Jane@example.com and jane@example.com remain separate entries.
Is this free, and are my inputs uploaded?
Use this tool without an account, subscription or credits. Processing and file exports run in your browser; the tool does not upload your inputs or send emails. Clear inputs to remove the current data. Inputs are not saved when you reload the page.
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