Best browser extensions for Gmail and email

Simplify Gmail changes how Gmail looks and behaves rather than adding a service on top of it. It is made by Michael Leggett, who describes himself in the store listing as a co-founder and design lead of Google Inbox. The idea is that Gmail's interface is cluttered and can be trimmed.

The features are practical. Hide parts of Gmail you never use, set list width and fonts, group mail with the same label into one row as bundles, and add saved searches to the sidebar. There is a pause-inbox mode for focus, auto-switching dark mode, arrow-key navigation and extra shortcuts. It also blocks more than 250 known email trackers, a count that comes from the developer.

On trust, it is one of the lighter-touch options. It asks for access to mail.google.com and Google's image host, not the Gmail API, and its listing says no data is collected, sent or stored and that there is no analytics or advertising. Those are the developer's claims and the code is not public. The cost is a paid plan once the free trial ends, and some reviewers dislike that. If you use Gmail on a desktop all day, this is the one we would try first.

Checker Plus for Gmail is a notifier that lives in your toolbar. Instead of keeping a Gmail tab open, you see unread counts, get desktop alerts and read, archive, mark as read or delete messages from a popup or the Chrome side panel. It is the work of one developer, Jason Savard, who has made a family of similar Google-related extensions.

Its strength is handling several accounts at once. It supports multiple Gmail and Google Workspace accounts, shows sender photos and can read new mail aloud, which helps with accessibility or multitasking. You can add your own notification sounds and voices. An optional AI feature drafts replies from a prompt, and it is off until you use it.

Because it works through Google's Gmail API, it asks for the gmail.modify scope, which allows reading, changing and deleting mail. The developer's privacy page says Google data is only displayed to you and not shared with anyone else, and that the AI feature sends the specific thread to Google's Gemini through a pass-through proxy that does not log it. That is the developer's statement, and the code is closed. It is free to use, with extra features unlocked by a contribution. A strong choice if you need alerts and several inboxes.

Trocker does one job: it stops senders from learning when you open their emails. Many newsletters and sales emails hide a tiny image that loads from the sender's server, and that request tells them you opened it. Trocker blocks those images, shows you which messages were tracked and tries to bypass links that log your clicks.

It works in the background on any site and adds extra features in Gmail, Yahoo Mail and Outlook.com. It matches known tracker addresses and uses a heuristic that treats very small images as trackers, since a sender who wants you to see an image will make it larger than one pixel. In Gmail and Yahoo, images load through a proxy, so it can block them. Outlook.com has no proxy, so there Trocker can expose a tracker but not always block it.

The trade-offs are honesty about reach and a small project. It needs access to all websites to catch trackers and bypass links, though the code is public on GitHub under Apache 2.0, and the developers say it makes no outbound network requests. A heuristic can miss trackers that avoid tiny images. If you want the free, open-source route to blocking email tracking, this is the one to install.

Mailvelope adds PGP encryption to webmail, so that only you and your recipient can read a message. Normally your email provider can read what you send. With Mailvelope the message is encrypted in your browser with the recipient's public key before it reaches Gmail or another provider. It is developed by Mailvelope GmbH in Germany.

You create or import a key, then compose in a separate Mailvelope window that your webmail cannot read. It works with Gmail and many other providers, and it has deeper integrations with WEB.DE, GMX and Posteo. A paid Mailvelope Business tier targets Nextcloud and Google Workspace, while the version for private users is free. The code is public on GitHub under AGPL-3.0.

Be realistic about the effort. End-to-end email only works when the other person also has PGP, and managing keys is not simple. Its privacy policy says that with the Gmail integration your email is not sent to Mailvelope's servers, but that keys can be uploaded to its key server and address lookups are sent, both on by default. It asks for all websites and Gmail API read and send scopes. It is the best fit for journalists, activists and anyone who already uses PGP.

Boomerang for Gmail is one of the older Gmail add-ons, made by Baydin Inc. The core idea is control over time: write a message now and send it later, pull a message out of your inbox until a date, or get a reminder if nobody replies. It has since added calendar scheduling, so you can propose meeting times from the compose window.

The free Basic plan has no time limit but gives 10 message credits a month. Paid plans lift that limit and add or expand features such as read receipts, recurring messages and Respondable, an assistant that predicts how likely a message is to get a response. New accounts get a trial of the paid plan.

The privacy cost is real. Boomerang works through your Google account, and its privacy policy says it collects the contents and header information of mail you send and receive, can store data outside the EU, and analyses message content with machine learning that you can switch off. The page we read is dated 2019. Its read receipts add a visible image to your outgoing mail and track link clicks, and recipients can opt out. It says it does not sell data. Use it if you need its scheduling, not for privacy.

Streak turns Gmail into a customer relationship manager. Instead of exporting contacts to a separate tool, you keep deals, hiring pipelines, support tickets and fundraising rounds as boxes inside your inbox, with the email threads attached. It is made by Streak (Rewardly, Inc., trading as Streak), a company that went through Y Combinator in 2011.

The free plan covers email tracking, snippets, shared threads and mail merge capped at 50 sends a day, but not the CRM pipelines, which start on Pro. Paid plans add shared pipelines, reports, integrations and automations, plus an AI assistant for summaries and data entry. The listing also mentions LinkedIn leads and mobile apps.

The trade-off is data. A CRM only works if its servers know about your conversations, and Streak's policy says it collects email metadata such as participants and headers, processes it in the United States and does not sell personal information. It does not make clear whether message bodies are stored, and it says it does not train generalised AI models on Google data. The extension needs access to Gmail and Streak's own domains. For a small sales team it is a strong pick, and for anyone else it is too much.