When comparing Gmail vs Slack, the Slant community recommends Gmail for most people. In the question“What are the best Material Design apps?” Gmail is ranked 10th while Slack is ranked 14th. The most important reason people chose Gmail is:
Gmail brings much of the functionality and power of Google's search engine to the app's search. You can use operators such as *label:*, *is:*, *OR*, *has:* among others, define date ranges, limit search to specific groups and so on. And, you can do it all amazingly fast. The search will also try to predict what you're trying to search for before you've even finished your query and offer up those results.
Ranked in these QuestionsQuestion Ranking
Pro Incredibly fast, advanced & predictive search
Gmail brings much of the functionality and power of Google's search engine to the app's search. You can use operators such as label:, is:, OR, has: among others, define date ranges, limit search to specific groups and so on. And, you can do it all amazingly fast. The search will also try to predict what you're trying to search for before you've even finished your query and offer up those results.
Pro Best support for Gmail features
Since both the Gmail Android app and Gmail itself is made by Google, the app supports all features Gmail offers (like labeling/starring) and gets new features implemented early - usually as soon as they are announced.
Pro Comes bundled with Android for free
Not only is the application free, it comes bundled with the Android OS by default so you don't even have to bother downloading it.
Pro Google Drive integration
The app allows inserting files from Drive straight to email or uploading attachments to Drive before sending them out. It will also notify if the person you're sending the file can open the file or if you should change the sharing settings for that file beforehand. Finally, you can choose which one of your Google accounts you want visible in the app.
Pro Google Calendar integration
Pro Tabs to automatically organize your e-mail
Gmail offers the ability to automatically organize your mail into specific categories:
Each of the categories can be disabled and you can move your mail around from category to category or set your own rules which sender should be put in which category.
Pro Threaded conversations
Pro Safely automatically displays images
The app does not require a confirmation to show images as Google now hosts the images on their own servers making it safe. You can still disable the automatic displaying of images in the settings if you wish.
Pro Robust integration with a huge number of tools
Slack integrates with tools like Trello, GitHub, Dropbox, Mailchimp, and dozens of others, so you can have a centralized event feed of your project right alongside your chat. This is tremendously useful for keeping context with your discussions.
You can ping people to get their attention even if they are not online by @mentioning them. Slack supports desktop notifications.
Pro Drag & drop files in channels
You can upload a file to any channel over HTTPS simply by dragging and dropping.
Pro Fantastic search functionality
You can deep search messages, files and snippets. Given Slacks integration into many external services, Slack is good enough to act as the central search interface for your entire team.
Pro Syntax coloring
Pasted code can be colored based on syntax.
Pro Very polished user experience
The entire Slack interface is polished and intuitive to use. There are very few bugs or inconsistencies in the UI and it's very fast to use. There is nothing in particular that is new with Slacks implementation of team chat, but the execution of the groups (called channels), search, external service integration and notifications is close to perfect.
Pro Apps for iOS, Android, Windows Phone, Mac OS, Linux, and Windows
Slack has apps for iOS, Android, Windows Phone, Mac OS, Linux, and Windows to give you the full functionality of Slack with some extra features not found on the website on most major platforms.
Pro Supports multiple teams
You can be signed into multiple teams simultaneously and quickly switch between them.
Pro Flexible, granular notification settings
Notifications are handled separately for mobile and the web app. You can receive notifications for all messages, just direct messages, or based on filters, and you can have different settings for different channels: you don't have to get notified every time someone pushed to GitHub or every time someone posts to off-topic chat, unless you want to.
Pro Freemium plan
Free forever, only restriction on searchable message archives, up to 10k of your team’s most recent messages and 10 apps or service integration. Great for trying out first.
Pro Slackbot extensible chat robot
The "Slackbot" can is an extensible robot that can be set you remind you about tasks, auto respond to certain phrases and a variety of other functionality.
Pro Inline link previews (photos, mockups, etc.)
When a link is added, some content in the link is shown such as image - like how Facebook does it when you share a link.
Pro Edit messages easily
It allows you to change what you sent by hovering to the message and selecting "Edit message" under the ellipsis (...).
Pro Emoji reactions to limit excessive posts and notifications
Pro Shows local time of each participant
You can click on the profile of a user to see their local time. An especially useful feature when members of your team are working in different timezones.
Pro Dev team is invested, responsive, and friendly
Having submitted both feedback and support requests for bot development, I can personally attest that the team takes feedback seriously, and responds quickly to communication. This is vital for any closed-source or hosted project.
Pro IRC connectivity over SSL
Pro Self chatting
Creative implementation which is very good for personal journaling or drafting/collecting ideas. Previously, to do this, users needed to create a private channel with themselves. Note that some other team-chat apps may disallow creating group/channel with no 2nd person(s).
Pro It can surprise you
There's a checkbox in preferences under advanced options that may surprise you.
Pro Multiple channels for different groups
Con Sorting mail by Unread is unintuitive
Nearly every other mail app has a clear way to sort mail by Unread. In Gmail app you can do that only by typing “label:unread” in the search field.
Con Very limited HTML composing
Composing of HTML formatted mails is very limited. No inline images and only some basic text formatting options
Con No intrinsic p2p encryption option
Con Too heavy
It should be lightweight.
Con Limited notification buttons
Con Expensive when you need to upgrade
At $6.67 per user / month (or $8 if billed monthly) , Slack is significantly more expensive than the competition if you need features such as unlimited integrations (more than 10) or unlimited message storage (more than 10,000). However, the free version of Slack includes unlimited users.
However if you need only unlimited messages you can use storage services like https://slarck.com to upload then browse and search your entire message history, while staying in Slack's free plan. So with a combo of Slack+Slarck this con is not that major.
Con No self-hosting available
If you are worried about third-parties getting access to your data you should consider self-hosting. With self-hosting you are in control over where your data is stored, who has access to it. You will also not be vulnerable to exploits of a third-party provider.
Con Hidden max limit of free users per channel
Slack says that their free accounts support an unlimited number of users, which is true. However they don't mention that there is an undisclosed maximum number of users per channel (8462). For a large open source community, this is something to keep in mind.
Con Proprietary (non-free/libre)
Con Linux client is very RAM intensive
Con "Native" desktop apps are web apps
While it's great that Slack provides installable apps for Windows, macOS, and Linux, they're just the Slack web app wrapped in Electron shell. This means they don't offer the same level of native UX that a truly native toolkit app would.
Con Slow and lags sometimes
Con API doesn't allow custom widgets in chat
Con Awful performance and constant glitches, since it is Chromium-based
You will experience a lot of hangs and glitches and it eats immense (for as basic as UI is) amount of RAM.
Con No E2E encryption
Data is sent of SSL only, not E2E encrypted.
Con API is overall very poor
Can't do much with integrations.