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APIs · head to head

Ably vs Zeplo

Ably logo

Ably

APIs

Realtime data delivery platform for pub/sub messaging at scale

From
Free
Rated
-
Full reviewWebsite
Zeplo logo

Zeplo

APIs

Message queue as a URL prefix, adding retries and delays to any HTTP request

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.; Zeplo zeplo sits directly in the execution path of your background work, so an outage at a very small vendor means your jobs do not run at all, and there is no published SLA below Enterprise.
  • They diverge on capability: Ably covers Pub/sub messaging, Zeplo covers URL prefix interface.
  • Prices and features above were last checked on 31 August 2026.

Where they differ

Only the attributes on which Ably and Zeplo actually diverge.

Attributes where Ably and Zeplo differ
AttributeAblyZeplo
Pricing modelfreemiumPer month by request count
Platformsweb, ios, android, apiWeb, Cloud

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 Zeplo

  • URL prefix interface
  • Retries with backoff
  • Delayed delivery
  • Cron scheduling
  • Concurrency limits
  • Deduplication keys
  • Request logs
  • Team workspaces

What people use each for

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

Ably

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

Zeplo

  • A Vercel or Cloudflare Workers application that needs retried background jobs without deploying a separate always-on workernot Ably
  • A team that wants a webhook receiver protected by a concurrency limit so a burst does not overwhelm a downstream APInot Ably
  • A small product needing cron jobs against HTTP endpoints without adding a scheduler to its infrastructurenot Ably
  • A developer adding idempotent retries to an unreliable third-party API call with a one-line URL changenot 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.

Zeplo

  • Zeplo sits directly in the execution path of your background work, so an outage at a very small vendor means your jobs do not run at all, and there is no published SLA below Enterprise.
  • The free Developer tier includes only 500 requests a month and one team member, so it is a demonstration allowance rather than a usable free plan for anything real.
  • Overage on the Developer tier is 20 US dollars per 100,000 requests, two hundred times the marginal rate on the Company tier, so exceeding the free allowance without upgrading is expensive.
  • Team members cost 15 US dollars each beyond the plan allowance, which is an odd charge on an infrastructure product billed by request volume.
  • Log retention is 30 days on both published tiers, so anything requiring longer audit trails on job execution has to be logged separately.

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

Zeplo

Free
  • DeveloperFree
    • 500 requests a month included
    • $20 per additional 100,000 requests
    • 1 team member
  • Company$39/month
    • 1,000,000 requests a month included
    • $10 per additional million requests
    • Up to 3 team members
  • Enterprise$undefined/month
    • Volume discounts
    • Custom team size
    • Support with SLA

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 Zeplo if

  • You need url prefix interface.
  • You want to start without paying.
  • You work on Web, Cloud.
  • You also want retries with backoff.
Zeplo review

Questions people ask

Is Ably or Zeplo better?
Neither clearly leads. Ably starts at Free and Zeplo at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Ably or Zeplo?
Ably starts at Free and Zeplo at Free.
Does Ably or Zeplo run on more platforms?
Ably runs on web, ios, android, api. Zeplo 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 Zeplo is typically brought in for.
What can Ably do that Zeplo cannot?
Ably covers Pub/sub messaging, Presence, Message persistence, Multi-protocol support. Zeplo covers URL prefix interface, Retries with backoff, Delayed delivery, Cron scheduling.

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
Zeplo: How does Zeplo work?

You prefix your endpoint URL with zeplo.to and add query parameters for retries, delay, cron or concurrency. No SDK or broker is needed.

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
Zeplo: What does it cost?

Free for 500 requests a month; 39 US dollars a month for a million requests, then 10 dollars per additional million.

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
Zeplo: Is it suitable for critical jobs?

It is a small vendor in your execution path with no published SLA below Enterprise, so weigh that against the convenience.

Zeplo: Does it work with serverless platforms?

Yes, that is its main use, covering Vercel, Cloudflare Workers, Netlify and similar environments that lack long-running workers.

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