Utility APIs
Free utility APIs with working curl examples: random user generation, name-based age and gender prediction, placeholder text and open institution datasets.
23 tested APIs with full docs · 23 need no key · 72 more listed
Tested, with full documentation
We called each of these before publishing. Every page carries a working curl command, the real JSON response it returned, parameters and common errors.
Agify
Free API that estimates age from a first name using public name data. No key for 100 requests/day. Tested curl example, live response and accuracy caveats.
Al Adhan Prayer Times
Free prayer times API with no key: daily Islamic prayer times for any city or coordinates, with multiple calculation methods and Hijri date conversion. Tested.
Bacon Ipsum
Free lorem ipsum style placeholder text API with no key. Generate meat-themed filler paragraphs or sentences via a simple GET request. Tested example.
BarcodeAPI.org
Free barcode generator API with no key: Code128, EAN, UPC, QR, Code39, ITF and more as PNG or base64 JSON from a plain URL. Tested example included.
Binlist
Free BIN lookup API with no key: identify the issuing bank, card scheme, type and country from the first digits of a card number. Tested curl example.
CalDays
Free public holiday API with no key: every holiday for a country and year, plus long weekends and a multi-city clock, under CC BY 4.0. Tested example included.
Church Calendar (Calapi)
Free Catholic liturgical calendar API with no key: today's celebrations, liturgical season, colour and feast rank for any date, in six languages. Tested example included.
CleanURI
Free URL shortener API with no key: shorten any link with a single POST request. No account, no tracking dashboard, just a short URL back. Tested example.
Colormind
Free AI colour palette API with no key: generate harmonious five-colour palettes, or lock colours and let the model complete the rest. Tested POST example.
DigiDates
Free date utility API with no key: validate dates, compute age, week numbers, leap years, Unix timestamps and progress through a period. Tested example included.
Genderize
Free API estimating the gender statistically associated with a first name, with a probability score. 100 requests/day, no key. Tested example and caveats.
Hebcal
Free Hebrew calendar API with no key: convert Gregorian to Hebrew dates and back, plus Jewish holidays, Shabbat times, Torah portions and yahrzeit calculations. Tested example included.
LectServe
Free lectionary API with no key: today's and Sunday's scripture readings from the Revised Common and ACNA lectionaries, with liturgical year and season. Tested example included.
Math.js API
Free maths API with no key: send an expression as a query parameter and get the evaluated result back as plain text. Handles units, matrices and functions. Tested example included.
Nationalize
Free API predicting likely nationality from a first name, returning ranked countries with probabilities. 100 requests/day, no key. Tested curl example.
Open Brewery DB
Free brewery directory API with no key: search breweries by name, city, state, country and type, with addresses and coordinates. Tested curl example.
PostalPincode.in
Free Indian pincode API with no key: look up every post office for a PIN code, or find PIN codes by post office name, with district, division and state. Tested example included.
Random User Generator
Free random user generator API with no key: names, addresses, emails, photos and logins in multiple nationalities. Seeded and reproducible. Tested example.
Random Word API
Free random word API with no key: generate one or many random English words, filtered by length. Minimal payload, useful for games and test data. Tested.
The Calendar
Free US holiday API with no key: federal and per-state holidays as static JSON files, each entry citing its statutory basis and observance rule. Tested example included.
TheColorAPI
Free colour API with no key: convert between hex, RGB, HSL, CMYK and XYZ, get human colour names, contrast values and generate colour schemes. Tested.
Universities List
Free university directory API with no key: search 9,000+ universities worldwide by country or name, with domains and web pages. Tested curl example.
UUIDGenerator.net
Free UUID API with no key: request version 1, 3, 4 or 5 identifiers and get them back as a JSON array, in bulk if needed. Tested example included.
Choosing between these Utility APIs
Utility APIs generate or infer data rather than looking it up. They are most useful for seeding databases, building realistic design mockups and filling test fixtures with data that looks plausible.
The name-analysis APIs — Agify, Genderize and Nationalize — are statistical estimators built from public name datasets. They return probabilities, not facts, and each page says so explicitly, because using them as ground truth about a real person is both inaccurate and a poor practice.
More Utility APIs in the directory
72 further APIs in this category, of which 26 need no API key. These are catalogued from the public-API lists and link straight to each provider's own documentation — we have not tested them yet, so treat the auth and CORS flags as the upstream list's claim rather than ours. They are promoted to a full tested page as we work through them.
| API | What it does | Auth |
|---|---|---|
| 1pt | A simple URL shortener | NoneCORS |
| Abstract Phone Validation | Validate phone numbers globally | KeyCORS |
| Abstract Public Holidays | Data on national, regional, and religious holidays via API | KeyCORS |
| Aftership | API to update, manage and track shipment efficiently | KeyCORS |
| Bitly | URL shortener and link management | OAuth |
| Bly.to | URL shortening service with analytics and tracking capabilities | KeyCORS |
| Calendarific | Worldwide Holidays | Key |
| Checkiday - National Holiday | Industry-leading holiday data with over 5,000 holidays and thousands of descriptions | Key |
| Church Calendar | Catholic liturgical calendar | None |
| ClickMeter | Monitor, compare and optimize your marketing links | Key |
| Clico | URL shortener service | Key |
| Correios | Integration to provide information and prepare shipments using Correio's services | Key |
| Cutt.ly | URL shortener service | Key |
| Czech Namedays Calendar | Lookup for a name and returns nameday date | None |
| Drivet URL Shortener | Shorten a long URL easily and fast | None |
| Eventbrite | Find events | OAuth |
| Festivo Public Holidays | Fastest and most advanced public holiday and observance service on the market | KeyCORS |
| Free Url Shortener | Free URL Shortener offers a powerful API to interact with other sites | None |
| Generate iCAL | Generates iCal calendar events that can be used across calendar applications | KeyCORS |
| Git.io | Git.io URL shortener | None |
| Google Calendar | Display, create and modify Google calendar events | OAuth |
| GoTiny | A lightweight URL shortener, focused on ease-of-use for the developer and end-user | NoneCORS |
| Hebrew Calendar | Convert between Gregorian and Hebrew, fetch Shabbat and Holiday times, etc | None |
| Holidays | Historical data regarding holidays | Key |
| iTunes | Apple Podcasts Directory | None |
| Kutt | Free Modern URL Shortener | KeyCORS |
| Linkly | URL shortener API with branded domains, click tracking, smart redirects, and webhooks | KeyCORS |
| Mgnet.me | Torrent URL shorten API | None |
| MobileAPI | Smartphone, tablet, and wearable device specifications | KeyCORS |
| Nager.Date | Public holidays for more than 90 countries | None |
| Namedays Calendar | Provides namedays for multiple countries | NoneCORS |
| Non-Working Days | Database of ICS files for non working days | None |
| Non-Working Days | Simple REST API for checking working, non-working or short days for Russia, CIS, USA and other | NoneCORS |
| Numlookup | Phone number validation and carrier lookup API with global coverage | Key |
| NumlookupAPI | Worldwide Phone Number Lookup & Verification API | KeyCORS |
| Numverify | Phone number validation | Key |
| OpenHolidays API | Public and school holidays for many countries via an open REST API | NoneCORS |
| owo | A simple link obfuscator/shortener | None |
| Particle | Podcast intelligence: podcast & episode search, transcripts, speakers, entity mentions, sponsor & advertising data, alerts and embeds | Key |
| Phone Specification | Rest Api for Phone specifications | NoneCORS |
| Phone Validation | Validate phone numbers globally | KeyCORS |
| Pixela | API for recording and tracking habits or effort, routines | KeyCORS |
| PodcastIndex | Get details on podcasts & episodes, Podcast Search | Key |
| Podchaser | Podcast Data API | The podcast API for discovery and insights. Access 6M+ podcasts with audience demographics, transcripts, Apple/Spotify charts. For media monitoring and intel | Key |
| PostalPinCode | API for getting Pincode details in India | None |
| Postmon | An API to query Brazilian ZIP codes and orders easily, quickly and free | None |
| PostNord | Provides information about parcels in transport for Sweden and Denmark | Key |
| Proweblook Phone Number Checker | Phone number validation | KeyCORS |
| Proweblook Whatsapp Contact Checker | Whatsapp number validation | KeyCORS |
| Public Holidays | Data on national, regional, and religious holidays via API | KeyCORS |
| Rebrandly | Custom URL shortener for sharing branded links | Key |
| RedirHub | URL redirect management with custom domains, HTTPS, analytics, and REST API | KeyCORS |
| Russian Calendar | Check if a date is a Russian holiday or not | None |
| SeatGeek | Search events, venues and performers | Key |
| Short Link | Short URLs support so many domains | None |
| Shrtcode | URl Shortener with multiple Domains | NoneCORS |
| Shrtlnk | Simple and efficient short link creation | KeyCORS |
| Spoo.me | Free URL shortener with custom alias, max-clicks, password protection and advanced analytics support | NoneCORS |
| Spotify | Get details on podcasts & episodes | OAuth |
| T.LY | URL shortener and link management service | KeyCORS |
| Taddy Podcasts | Get details on podcasts & episodes, Podcast & Episode Search, Webhook notifications | KeyCORS |
| Ticketmaster | Search events, attractions, or venues | Key |
| TinyURL | Shorten long URLs | Key |
| UK Bank Holidays | Bank holidays in England and Wales, Scotland and Northern Ireland | None |
| UPS | Shipment and Address information | Key |
| UrlBae | Simple and efficient short link creation | KeyCORS |
| Urlmskr | Easy and fast masked, shortened link creation | None |
| Veriphone | Phone number validation & carrier lookup | KeyCORS |
| VeriRoute Intel | CNAM caller ID, carrier/LRN lookup and spam scoring for North American phone numbers | Key |
| WeCanTrack | Automatically place subids in affiliate links to attribute affiliate conversions to click data | KeyCORS |
| WhatPulse | Small application that measures your keyboard/mouse usage | None |
| WhereParcel | Unified parcel tracking API across 60+ carriers worldwide (USPS, FedEx, UPS, DHL, etc.) | KeyCORS |