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APIs · head to head

Ably vs Stoplight

Ably logo

Ably

APIs

Realtime data delivery platform for pub/sub messaging at scale

From
Free
Rated
-
Full reviewWebsite
Stoplight logo

Stoplight

APIs

API design, documentation, and governance platform

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: Ably standard and Pro plans layer usage-based charges for messages, connection minutes, and data transfer on top of the base subscription, adding cost complexity.; Stoplight the free plan allows one project and one user
  • They diverge on capability: Ably covers Pub/sub messaging, Stoplight covers API Design.
  • Prices and features above were last checked on 30 August 2026.

Where they differ

Only the attributes on which Ably and Stoplight actually diverge.

Attributes where Ably and Stoplight differ
AttributeAblyStoplight
Pricing modelfreemiumsubscription
Platformsweb, ios, android, apiWeb, Cloud
FoundedUnknown2014

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

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 Ably

  • Pub/sub messaging
  • Presence
  • Message persistence
  • Multi-protocol support
  • Encryption
  • Datadog integration

Only in Stoplight

  • API Design
  • API Documentation
  • Governance
  • GitHub
  • GitLab
  • Jenkins
  • Azure DevOps
  • Web support

What people use each for

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

Ably

  • Building realtime chat or collaborative appsnot Stoplight
  • Delivering live data feeds like stock prices or sports scoresnot Stoplight
  • Broadcasting notifications to many concurrent clientsnot Stoplight
  • Running mission-critical realtime infrastructure with high uptime SLAsnot Stoplight

Stoplight

  • API design and documentationnot Ably
  • API governance and standardsnot Ably
  • Team collaboration on API developmentnot Ably
  • API mocking and testingnot Ably

Where each one falls short

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

Ably

  • Standard and Pro plans layer usage-based charges for messages, connection minutes, and data transfer on top of the base subscription, adding cost complexity.
  • The jump from Standard ($29/month) to Pro ($399/month) is steep for teams needing more than 10k connections but not full Pro capacity.
  • 24/7 mission-critical support and 99.999% uptime SLAs are reserved for the custom-priced Enterprise tier.

Stoplight

  • The free plan allows one project and one user
  • Private projects, multi branch support and custom domains start at the Startup plan, $113 a month billed annually
  • SSO and shared style guides are Pro Team only, at $362 a month billed annually
  • Seats beyond each plan's allowance are $11 to $27 each per month depending on tier and billing period

Pricing, plan by plan

Ably

Free
  • FreeFree
    • 200 concurrent connections
    • 500 messages/second
    • 6M messages/month
  • Standard$29/month
    • 10k concurrent channels
    • 10k concurrent connections
    • 2.5k messages/second
  • Pro$399/month
    • 50k concurrent channels
    • 50k concurrent connections
    • 10k messages/second

Stoplight

Free
  • FreeFree
    • 1 project
    • 1 user
    • Basic API design and documentation features
  • Basic$56/month
    • Annual: $44/user/year
    • 3 included users; $14 per additional user (monthly)
    • Unlimited projects
  • Startup$147/month
    • Annual: $113/user/year
    • 8 included users; $14 per additional user (monthly)
    • Private projects
  • Pro Team$453/month
    • Annual: $362/user/year
    • 15 included users; $27 per additional user (monthly)
    • Up to 20 teams

Which should you pick?

Choose Ably if

  • You need pub/sub messaging.
  • You want to start without paying.
  • You work on web, ios, android, api.
  • You also want presence.
Ably review

Choose Stoplight if

  • You need api design.
  • You want to start without paying.
  • You work on Web, Cloud.
  • You also want api documentation.
Stoplight review

Questions people ask

Is Ably or Stoplight better?
Neither clearly leads. Ably starts at Free and Stoplight at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Ably or Stoplight?
Ably starts at Free and Stoplight at Free.
Does Ably or Stoplight run on more platforms?
Ably runs on web, ios, android, api. Stoplight runs on Web, Cloud.
Can I use Ably for free?
Both have a free tier, so you can try either at no cost before committing.
What is Ably best used for?
Ably is most often used for building realtime chat or collaborative apps, delivering live data feeds like stock prices or sports scores, broadcasting notifications to many concurrent clients, running mission-critical realtime infrastructure with high uptime slas. Of those, building realtime chat or collaborative apps and delivering live data feeds like stock prices or sports scores are not what Stoplight is typically brought in for.
What can Ably do that Stoplight cannot?
Ably covers Pub/sub messaging, Presence, Message persistence, Multi-protocol support. Stoplight covers API Design, API Documentation, Governance, GitHub.

Answered from the vendors’ own pages

Ably: What does Ably cost?

Ably offers a free plan with 200 concurrent connections, a Standard plan at $29/month plus usage, a Pro plan at $399/month plus usage, and custom Enterprise pricing with unlimited channels and connections.

Source
Stoplight: How much does Stoplight cost?

Stoplight starts with a free plan (1 project, 1 user), then Basic at $56/month per user (or $44/year), Startup at $147/month per user (or $113/year), Pro Team at $453/month per user (or $362/year), and Enterprise at custom pricing.

Source
Ably: Is there a free plan, and what are its limits?

Yes, the free plan includes 200 concurrent connections, 500 messages per second, and 6 million messages per month with community and best-effort email support.

Source
Stoplight: How many included users are in each Stoplight plan?

Basic includes 3 users, Startup includes 8 users, and Pro Team includes 15 users. Additional users beyond the included count cost $14/month for Basic and Startup, or $27/month for Pro Team.

Source
Ably: How is usage metered?

Beyond plan limits, Ably charges usage-based rates of $2.50 per million messages, $1.00 per million connection minutes, $1.00 per million channel minutes, and $0.25 per GiB of data transfer, with volume discounts available.

Source
Stoplight: Does Stoplight offer a free trial?

Yes, all paid Stoplight plans include a 14-day free trial. The free plan has no trial period as it is always available.

Source
Stoplight: Does Stoplight's free plan have limitations?

Yes, the free plan includes only 1 project and 1 user. Users viewing public documentation anonymously are not counted toward the 1-user limit.

Source
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