Softwr

Communication · head to head

Messenger vs Slack

Messenger logo

Messenger

Communication

Meta's standalone messaging app for Facebook, with end to end encryption on by default since 2023

From
Free
Rated
-
Full reviewWebsite
Slack logo

Slack

Communication

Where work happens

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: Messenger while message content is end-to-end encrypted by default since December 2023, metadata such as who messaged whom and when is not encrypted and remains visible to Meta.; Slack 90-day message history limit on free plan results in important conversations disappearing
  • They diverge on capability: Messenger covers End-to-end encrypted chats, Slack covers Channels.
  • Prices and features above were last checked on 1 September 2026.

Where they differ

Only the attributes on which Messenger and Slack actually diverge.

Attributes where Messenger and Slack differ
AttributeMessengerSlack
Pricing modelFree, funded by Meta's advertising businessUnknown
PlatformsiOS, Android, WebWeb, iOS, Android, macOS, Windows, Linux
FoundedUnknown2009

Identical on both: starting price (Free), free tier (Yes), user rating (Not yet rated), category (Communication).

What each one covers

Drawn from each product's published feature list. An absence here means we hold no record of it - not that the product lacks it.

Only in Messenger

  • End-to-end encrypted chats
  • Voice and video calling
  • Marketplace messaging
  • Disappearing messages
  • Cross-app chat with Instagram
  • Business messaging

Only in Slack

  • Channels
  • Direct messaging
  • Voice & video calls
  • Screen sharing
  • File sharing
  • Search
  • Workflow builder
  • Slack Connect

What people use each for

The jobs each tool is most often brought in to do.

Messenger

  • Messaging friends and family who primarily use Facebook rather than a phone number based appnot Slack
  • Coordinating a buy or sell exchange through Facebook Marketplace messagingnot Slack
  • Making free video or voice calls to contacts without needing their phone numbernot Slack
  • Messaging a business through its Facebook Page for customer servicenot Slack

Slack

  • Team communicationnot Messenger
  • Project coordinationnot Messenger
  • Customer supportnot Messenger
  • Remote worknot Messenger
  • Cross-functional collaborationnot Messenger

Where each one falls short

Documented limitations, not opinions. Every one is a constraint you would hit in normal use.

Messenger

  • While message content is end-to-end encrypted by default since December 2023, metadata such as who messaged whom and when is not encrypted and remains visible to Meta.
  • Full functionality generally assumes a linked Facebook account, which ties messaging to a broader social profile many users would rather keep separate.
  • Cloud chat backups, if enabled, are protected by a PIN the user sets, and losing that PIN without a recovery key can mean losing access to backed-up chat history.
  • As a Meta product, its business model depends on the surrounding Meta advertising ecosystem, and account-level data outside message content still feeds that system.
  • Group chat and calling features have historically launched later or with more limitations on Messenger than on some competing apps built encryption-first from the start.

Slack

  • 90-day message history limit on free plan results in important conversations disappearing
  • Per-user pricing becomes expensive quickly for larger teams
  • Notification overload with 78% of employees feeling overwhelmed by notifications
  • Mobile app performance issues including lag and slow syncing
  • Huddles limited to 50 people and cannot be recorded
  • Requires dedicated video conferencing service for formal meetings and webinars

Pricing, plan by plan

Messenger

Free
  • FreeFree
    • Unlimited messaging, calling and group chats
    • No subscription tier

Slack

Free

No published plan breakdown. See the Slack review.

Which should you pick?

Choose Messenger if

  • You need end-to-end encrypted chats.
  • You want to start without paying.
  • You work on iOS, Android, Web.
  • You also want voice and video calling.
Messenger review

Choose Slack if

  • You need channels.
  • You want to start without paying.
  • You work on Web, iOS, Android, macOS, Windows, Linux.
  • You also want direct messaging.
Slack review

Questions people ask

Is Messenger or Slack better?
Neither clearly leads. Messenger starts at Free and Slack at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Messenger or Slack?
Messenger starts at Free and Slack at Free.
Does Messenger or Slack run on more platforms?
Messenger runs on iOS, Android, Web. Slack runs on Web, iOS, Android, macOS, Windows, Linux.
Can I use Messenger for free?
Both have a free tier, so you can try either at no cost before committing.
What is Messenger best used for?
Messenger is most often used for messaging friends and family who primarily use facebook rather than a phone number based app, coordinating a buy or sell exchange through facebook marketplace messaging, making free video or voice calls to contacts without needing their phone number, messaging a business through its facebook page for customer service. Of those, messaging friends and family who primarily use facebook rather than a phone number based app and coordinating a buy or sell exchange through facebook marketplace messaging are not what Slack is typically brought in for.
What can Messenger do that Slack cannot?
Messenger covers End-to-end encrypted chats, Voice and video calling, Marketplace messaging, Disappearing messages. Slack covers Channels, Direct messaging, Voice & video calls, Screen sharing.

Answered from the vendors’ own pages

Messenger: Is Messenger encrypted by default now?

Yes, since December 2023 personal chats and calls are end-to-end encrypted by default, moving on from the earlier opt-in Secret Conversations mode.

Slack: Does Slack have a free plan?

Yes, Slack offers a free plan indefinitely with no credit card required. Free users get 90-day message history, up to 10 app integrations, and 1:1 huddles.

Source
Messenger: What can Meta still see if chats are encrypted?

Metadata such as who is messaging whom, when, and group membership is not encrypted and remains visible to Meta, even though message content is.

Slack: What are Slack's pricing plans?

Slack offers Free, Pro ($7.25/user/month with annual billing), Business+ ($12.50/user/month), and Enterprise Grid (custom pricing). Monthly billing costs approximately 20% more than annual.

Source
Messenger: Do I need a Facebook account to use Messenger?

In some markets Messenger can be used with just a phone number, but most features assume a linked Facebook account.

Slack: Does Slack support offline use?

Slack is a cloud-based platform and does not support robust offline work. Internet connectivity is required to access messages and collaborate.

Source
Slack: What integrations does Slack support?

Slack integrates with 43+ apps on average per team, including Google Drive, ChatGPT, Vercel, Asana, GitHub, and many others through their app marketplace.

Source
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