1. Mailtrack
Read receipts and link tracking for Gmail.
Why it replaces SONAR Email Tracker for Gmail - Secure & Free: Covers similar ground in the Email category: Read receipts and link tracking for Gmail.
Best SONAR Email Tracker for Gmail - Secure & Free Alternatives in 2026
SONAR Email Tracker for Gmail - Secure & Free is a strong option, but it is not the right fit for everyone. Below are 10 alternatives compared on rating, install base, pricing and the use case each one actually wins on.
About SONAR Email Tracker for Gmail - Secure & Free
Unlimited and forever free tool to track your emails easily.
Free
Full reviewComparison at a glance
| Extension | Rating | Users | Pricing | Best for |
|---|---|---|---|---|
| SONAR Email Tracker for Gmail - Secure & Free (original) | — | — | Free | Unlimited and forever free tool to track your emails easily. |
| Mailtrack | 4.4 | 3M+ | Freemium | Salespeople and recruiters who need to know when an email was actually opened. |
| Apollo.io: Free B2B Phone Number & Email Finder | — | — | Free | Apollo enables users to find contact info, connect with buyers, track emails, and more for free. |
| HubSpot Sales | — | — | Free | Email tracking, CRM for Gmail, and sales productivity tools in your inbox |
| Email Finder by ContactOut – Email Lookup Tool | 4.4 | 600K+ | Free | Find emails for 75% of Linkedin or ANY website. Save profiles to CRM. Chatgpt comments & email writer. Trusted by 76% of Fortune500. |
| Email Finder by Snov.io | 4.9 | 400K+ | Free | Find email addresses on any website. Our Email Finder lets you collect leads and grow sales on the go. |
| GMass: Powerful mail merge for Gmail | 4.8 | 400K+ | Freemium | A powerful mass email and mail merge system for Gmail. |
| DocHub - Sign PDF from Gmail | 4.4 | 300K+ | Free | Sign and edit PDF documents |
| Compose AI: AI-powered Writing Tool | 4.1 | 300K+ | Freemium | Generate any text using AI. Autocomplete your sentences where you type. |
| WiseStamp Email Signature Chrome Extension | 3.9 | 200K+ | Free | WiseStamp email signature |
| ClickUp: Tasks, Screenshots, Email, Time | — | — | Free | ClickUp is a productivity platform that makes your personal and work lives more productive, saving you time. |
SONAR Email Tracker for Gmail - Secure & Free alternatives in detail
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2. Apollo.io: Free B2B Phone Number & Email Finder
Apollo enables users to find contact info, connect with buyers, track emails, and more for free.
Why it replaces SONAR Email Tracker for Gmail - Secure & Free: Covers similar ground in the Email category: Apollo enables users to find contact info, connect with buyers, track emails, and more for free.
3. HubSpot Sales
Email tracking, CRM for Gmail, and sales productivity tools in your inbox
Why it replaces SONAR Email Tracker for Gmail - Secure & Free: Covers similar ground in the Email category: Email tracking, CRM for Gmail, and sales productivity tools in your inbox
4. Email Finder by ContactOut – Email Lookup Tool
Find emails for 75% of Linkedin or ANY website. Save profiles to CRM. Chatgpt comments & email writer. Trusted by 76% of Fortune500.
Why it replaces SONAR Email Tracker for Gmail - Secure & Free: Covers similar ground in the Email category: Find emails for 75% of Linkedin or ANY website. Save profiles to CRM. Chatgpt comments & email writer. Trusted by 76% of Fortune500.
5. Email Finder by Snov.io
Find email addresses on any website. Our Email Finder lets you collect leads and grow sales on the go.
Why it replaces SONAR Email Tracker for Gmail - Secure & Free: Covers similar ground in the Email category: Find email addresses on any website. Our Email Finder lets you collect leads and grow sales on the go.
6. GMass: Powerful mail merge for Gmail
A powerful mass email and mail merge system for Gmail.
Why it replaces SONAR Email Tracker for Gmail - Secure & Free: Covers similar ground in the Email category: A powerful mass email and mail merge system for Gmail.
7. DocHub - Sign PDF from Gmail
Sign and edit PDF documents
Why it replaces SONAR Email Tracker for Gmail - Secure & Free: Covers similar ground in the Email category: Sign and edit PDF documents
8. Compose AI: AI-powered Writing Tool
Generate any text using AI. Autocomplete your sentences where you type.
Why it replaces SONAR Email Tracker for Gmail - Secure & Free: Covers similar ground in the Email category: Generate any text using AI. Autocomplete your sentences where you type.
9. WiseStamp Email Signature Chrome Extension
WiseStamp email signature
Why it replaces SONAR Email Tracker for Gmail - Secure & Free: Covers similar ground in the Email category: WiseStamp email signature
10. ClickUp: Tasks, Screenshots, Email, Time
ClickUp is a productivity platform that makes your personal and work lives more productive, saving you time.
Why it replaces SONAR Email Tracker for Gmail - Secure & Free: Covers similar ground in the Email category: ClickUp is a productivity platform that makes your personal and work lives more productive, saving you time.
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Frequently asked questions
What is the best alternative to SONAR Email Tracker for Gmail - Secure & Free?
Mailtrack is the closest match. Covers similar ground in the Email category: Read receipts and link tracking for Gmail.
Is there a free alternative to SONAR Email Tracker for Gmail - Secure & Free?
Yes — Apollo.io: Free B2B Phone Number & Email Finder, HubSpot Sales, Email Finder by ContactOut – Email Lookup Tool are free.