無料でメールリストをクリーンアップ — 重複排除と検証

A messy email list hurts your deliverability and wastes your marketing budget. Paste your list and get a clean, deduplicated, validated file in seconds.

メールリストを整理する必要があるのでしょうか?

Duplicate emails mean you pay twice for the same contact. Invalid emails bounce, damaging your sender reputation. Cleaning before every campaign is the simplest way to improve open rates and protect your domain.

このツールは何を削除しますか?

The tool removes exact duplicates, flags invalid formats, normalizes everything to lowercase, and exports a clean CSV ready for Mailchimp, Brevo, HubSpot or any other platform. It also tells you exactly how many duplicates and invalids were found.

私のリストは非公開ですか?

Completely. Your email list is processed in your browser and never sent to our servers. This is especially important for GDPR-regulated lists or confidential business contacts that you cannot risk uploading to a third-party service.

ブラウザベースのユーティリティ ツールを使用する理由は何ですか?

Online utilities like password generators, text formatters, and URL cleaners are convenient, but most send your data to remote servers. Our browser-based tools process everything locally — your passwords, text, and URLs never leave your device.

This is especially important for sensitive operations like generating passwords, checking password strength, or cleaning URLs that contain tracking parameters. With Presend, you get the convenience of online tools with the security of offline software.

当社のユーティリティツールがあなたのプライバシーをどのように保護するか

1. All processing happens in your browser using JavaScript
2. No data is transmitted to external servers
3. No cookies or tracking scripts monitor your usage
4. Your input data is cleared when you close the tab

当社のユーティリティ ツールを使用すると何ができるでしょうか?

Generate cryptographically secure passwords, check password strength against entropy analysis, convert between JSON and CSV formats, compare text differences, split long text into social media threads, clean tracking parameters from URLs, validate email lists, check color contrast for accessibility, and convert images to Base64 for embedding.

これらのツールは本当に無料ですか?

Yes — all our utility tools are completely free to use, with no registration required, no usage limits, and no watermarks. We believe privacy tools should be accessible to everyone, not locked behind paywalls or subscription models.