
Postio.co.uk
Ideal postcodes
Fetchify
Smarty
Data8 UK
ZIP Code API
Data8 UK PredictiveAddress
The most affordable postal code API. 240+ countries, sub-5 ms responses. Simple, elegant, transparent.

Calendly
Acuity Scheduling
TidyCal
zcal
SavvyCal
SetMore
Doodle
Cal.com (formerly Calendso) is the open source Calendly alternative.

Which is more popular?
Based on our record, Cal.com seems to be more popular. It has been mentioned 60 times since March 2021.
Website, pricing, platforms and company facts side by side.
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| Website | postaldatapi.com | cal.com |
| Pricing | ||
| Company | Startup from the United States · 1 - 9 employees · 2026 | — |
| Listed in |
In their own words, as submitted to SaaSHub.


PostalDataPI is a global postal code validation and enrichment API covering 240+ countries and territories. One API, one key, one flat rate — $0.000028 per query with no tiers or subscriptions. What you get back: Up to 18 metadata fields per postal code — city, state/region, coordinates,...
No description of Cal.com yet.
What each product offers, as listed by its team.


Possible disadvantages
Possible disadvantages
An editorial look at what each product does well and who it suits.


Overall verdict
Why this product is good
Recommended for
Overall verdict
Why this product is good
Recommended for
Walkthroughs and reviews on video.
PostalDataPI Now Returns 18 Fields Per Postal Code — for 240+ Countries
More videos
What can you do with Cal? | Cal.com Version 1.1 Launch | 10 new languages
More videos
How often each product is chosen within a category, 0–100% relative to the other.


Share your experience with using PostalDataPI and Cal.com. For example, how are they different and which one is better?
External articles and on-site reviews we used to compare the two products.


We have no reviews of PostalDataPI yet. Be the first one to post
The honest read: if you're leaving Acuity because your business outgrew simple scheduling — you need deposits, add-ons, multiple staff and locations, and ideally a booking site you own — Opencals is built for exactly...
I tried using https://cal.com for a bit but ended up just switching over to https://zcal.co and it has been great so far. All these other scheduling tools end up trying to do too much and always seem to end up a bit...
Recommendations tracked on public social media and blogs since March 2021.


Tracking PostalDataPI since Apr 2026.
Then for the component library, I was really into coss ui. I stumbled upon it randomly one day and loved it so much. My Nathan's AI project already had a UI heavily inspired by cal.com: send button, message suggestions... So when I saw... - Source: dev.to / 7 months ago
I keep coming back to what would have happened if I didn't have a strong technical understanding of how calendar technology works — the difference between local and cloud calendars, what an ICS feed is, why enterprise auth blocks... - Source: dev.to / 7 months ago
Plausible brought open source to web analytics. Cal.com did it for scheduling. Formbricks did it for surveys. PostHog did it for product analytics. Quackback does it for feedback collection. - Source: dev.to / 8 months ago
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