REST Countries has been a go-to free API for country data since 2014. It's simple, requires no API key, and covers the basics well. But if you've been using it for a while, you may have noticed some turbulence — ownership changes, archived repositories, and breaking updates that arrived without much warning.

World Data API takes a different approach: paid tiers with a permanent free option, but with regions, cities, and support included. Here's how they compare.

REST Countries remains active, but its history has been bumpy:

• The original GitHub repository was archived on June 19, 2024

• The project is now community-maintained on GitLab

• Ownership has changed hands, which has led to unexpected breaking changes in the past

None of this means REST Countries is unreliable today. The community has kept it running, and millions of requests hit it daily. But if you're building something for production, you should know that there's no company behind it, no SLA, and no guaranteed support channel.

REST Countries gives you solid country-level data with 30+ fields per country. If that's all you need, it works.

World Data API adds the layer below countries — regions like California, Bavaria, or Queensland — and the layer below that — cities. You also get holidays, business day calculations, and timezone utilities that REST Countries doesn't cover.

REST Countries: Free. No API key required. No rate limits published, though the /all endpoint caps you at 10 fields per request due to load (they handle around 4 million requests daily).

World Data API:

All paid tiers share a 1,000 requests/hour rate limit.

REST Countries wins on price if you're building a hobby project or need occasional country lookups. World Data API makes sense when you need higher volume, additional data types, or someone to email when something breaks.

Both APIs are RESTful and return JSON. Here's how basic country lookups compare:

REST Countries (v3.1):

GET https://restcountries.com/v3.1/alpha/US
GET https://restcountries.com/v3.1/name/germany
GET https://restcountries.com/v3.1/all?fields=name,capital,currencies

World Data API:

GET https://api.worlddata.ai/v1/countries/US
GET https://api.worlddata.ai/v1/countries?name=germany
GET https://api.worlddata.ai/v1/countries

REST Countries offers more filtering options out of the box — you can search by currency, language, or region directly in the URL. World Data API requires query parameters for most filtering but gives you regions and cities as separate endpoints.

• You need country data only, no regions or cities

• You're building a side project or prototype

• You want zero cost and no API key management

• You're comfortable with community-maintained infrastructure

• You need regions or cities, not just countries

• You want stable versioning and someone to contact when things break

• You're building for production and need predictable uptime

• You need holidays, business days, or timezone calculations

• Your volume exceeds what feels reasonable on a free community API

REST Countries:

• No regions or subdivisions

• No cities

• No holidays or business day logic

• Community-maintained with no formal support

• History of ownership changes and breaking updates

World Data API:

• Not free for higher volumes ($9/month minimum)

• City lookups with ambiguous names return null — use GeoNames ID or coordinates for reliability

• Around 12,000 cities total, not comprehensive for small towns

• No postal code data

• No proximity or radius search

REST Countries is a good free API for country data. If you just need ISO codes, capitals, currencies, and flags, it handles that without costing anything.

World Data API costs money but gives you more: 5,053 regions, 12,103 cities, holidays, business days, and a support channel. It's built for production use cases where you need data below the country level or can't afford to debug API issues alone.

Pick REST Countries if free and simple is what you need. Pick World Data API if you've outgrown country-only data or want the stability of a supported product.