Suggestions appear as you type. Use the up and down arrows to choose one and Enter to open it.

This page's audience our own tag's counts — open to see them
–Visits
–Page views
–Clicks to vendors
–Time on page
–Reading now
Clicks to vendors, by tool
  • –
Top countries
  • –
Devices
  • –

– · visits, page views and clicks counted by our own tag, which counts more than our checked analytics; every figure rounded down · how we count

Head-to-head · Instant Messaging Software

WhatsApp vs Slack

  • Updated Oct 2026
  • Both researched from official sources
  • 2 checks side by side
Higher score WhatsApp #1 in Instant Messaging Software 9.4/10 Free plan Free plan✓ 0 of 2 features Visit WhatsApp
Slack #6 in Instant Messaging Software 8.9/10 Free plan Free plan✓ 1 of 2 features Visit Slack

WhatsApp leads on 0 checks, Slack on 0, and 2 are even. Who comes out ahead on the 2 yes/no, price and count checks where we have data for both products. The editor score weighs everything else too.

Our verdict

  • Highest scoreWhatsApp · 9.4/10
  • Free planboth
  • Most featuresSlack · 1 of 2

WhatsApp scores higher on our rubric for instant messaging software: 9.4 against 8.9 out of 10; our editors rank them #1 and #6.

WhatsApp is the better fit for broad personal messaging and calling. Slack is the better fit for teams coordinating work across connected tools.

  • WhatsApp fits best

    Broad personal messaging and calling

  • Slack fits best

    Teams coordinating work across connected tools

Advertiser disclosure: iTechGuides is reader-supported. Vendors can pay for top positions in our rankings and for a place on other products' pages, and we may earn a commission when you click some links. Bought places stand at the number bought; this page and our disclosure say so. Paying vendors may get a fuller, more detailed review from our editors, and that review can change their score. How we rank.

Side by side

Feature WhatsApp 9.4/10 Visit ↗ Slack 8.9/10 Visit ↗
At a glance
Editor score 9.4 8.9
Ranking #1 in Instant Messaging Software #6 in Instant Messaging Software
Best for Broad personal messaging and calling Teams coordinating work across connected tools
Pricing model Free Free plan + paid
Starting price Free plan $7.25/user/mo
Free plan ✓ ✓
Free trial — —
Deployment Desktop, Mobile Cloud, Desktop, Mobile
Platforms Web, Windows, macOS, iOS, Android Web, Windows, macOS, Linux, iOS, Android
Support Docs Docs · 24/7
Compliance 2FA SOC 2, ISO 27001, GDPR, HIPAA, SSO/SAML, 2FA
Built for Solo, Small business Small business, Mid-market, Enterprise
Features WhatsApp 0/2 · Slack 1/2
End-to-end encryption Not checked yet Not checked yet
Guest access Not checked yet ✓ (best)
Specs
Message history Not checked yet Limited
Max group size Not checked yet Not checked yet
File size limit Not checked yet Not checked yet
Supported platforms Not checked yet Not checked yet
Our review
Pros
  • End-to-end encrypted personal messages and calls by default
  • Groups support up to 1,024 members with voice and video calls
  • Web, desktop, and mobile apps support up to four linked devices
  • Public and private channels organize team conversations.
  • Slack Connect supports collaboration with external organizations.
  • Workflow Builder, huddles and AI summaries extend beyond messaging.
Cons
  • Business and Meta AI conversations can have different privacy properties
  • Support is provided through documentation
  • The software is not open source
  • Free includes only 90 days of message history.
  • Free limits integrations to 10 apps and meetings to 1:1.
  • Pro and Business+ charge per user; Enterprise+ pricing is not shown here.
Our verdict

WhatsApp is a free messaging and calling application for personal communication across web browsers, Windows, macOS, iOS, and Android. It supports text, photo, video, document, and location sharing, plus voice and video calls, status…

Read the review →

Slack brings workplace conversations into channels, direct messages and huddles, with files, app connections and workflow automation alongside them. It suits teams that want a shared place to coordinate work, whether they are small…

Read the review →
  1. WhatsAppInstant Messaging Software 9.4Free plan
  2. SlackInstant Messaging Software 8.9Free plan

Strengths and trade-offs

  • WhatsApp — where it wins

    • End-to-end encrypted personal messages and calls by default
    • Groups support up to 1,024 members with voice and video calls
    • Web, desktop, and mobile apps support up to four linked devices

    Where it doesn't

    • Business and Meta AI conversations can have different privacy properties
    • Support is provided through documentation
    • The software is not open source

  • Slack — where it wins

    • Public and private channels organize team conversations.
    • Slack Connect supports collaboration with external organizations.
    • Workflow Builder, huddles and AI summaries extend beyond messaging.

    Where it doesn't

    • Free includes only 90 days of message history.
    • Free limits integrations to 10 apps and meetings to 1:1.
    • Pro and Business+ charge per user; Enterprise+ pricing is not shown here.
  • WhatsApp9.4/10 · Free plan

    A free, cross-platform messenger for personal chats, calls, groups, and sharing.

    Visit WhatsAppFull verdict →
  • Slack8.9/10 · Free plan

    Channels, messaging, huddles and integrations connect workplace collaboration in one service.

    Visit SlackFull verdict →

More comparisons

All instant messaging software comparisons → · Full ranking →

Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026

Last updated · How we research and update