Convert Any Webpage to Markdown: Tested on 40 Sites
Turn a URL into clean Markdown for an LLM or RAG index. We ran 40 real sites through it: 35 worked, 5 refused. Node.js crawler code included.
APIVerve Team
The people who build and run the APIVerve API catalog.
- 65 posts
Build a Translation App in Vue with a Translator API
Build a Vue 3 translator app with the APIVerve Translator API: working fetch code, auto-detection, a key-safe proxy, and a full GitHub repo. Start free.
Business Days Between Dates in JS, With Holidays
Count business days between two dates in JavaScript with real public holidays. Five bugs we hit, including one in our own API, and code that avoids them.
7 SSL Certificate Problems That Kill Trust
Expired certs, mismatched domains, weak encryption. A practical checklist for catching SSL issues before your users do.
Enrich CRM Records with a Company Lookup API
Enrich CRM leads with SEC company data in Node.js: match by ticker or name, map fields to CRM columns, and write an enriched CSV. Free API key.
Generate Barcodes in Node.js with an API
Generate Code 128 and Code 39 barcodes in Node.js with one POST request. Working Express code, real API responses, and a GitHub repo you can clone.
Summarize Text with an API in Python
How to summarize text with a text summarization API: a curl request, then a Python script that summarizes support tickets to JSON and CSV. Try it free.
Generate a PDF from HTML in Node.js: What Works
HTML to PDF in Node.js with a working invoice example. We tested page breaks, repeated headers, web fonts, page numbers, JavaScript and page size.
How to Detect VPN Users: Tested on 4,690 IPs
We ran Mullvad, IVPN, Tor and 2,852 home connections through VPN, Tor and blacklist checks. What each one catches, and Node.js middleware to use them.
Password Generator API: Secure Temp Passwords in Node
Generate temporary passwords with a password generator API, hash them with argon2, and check strength in Node.js. Copy-paste code inside.
DNS Lookups: A Developer's Debugging Guide
DNS problems cause connection failures and email issues. Learn how to use DNS lookups to diagnose problems faster.
Prevent Fake Signups: What Our Gate Blocked in 30 Days
30 days of APIVerve signup logs: 436 accounts, 99 refusals from 36 IPs, all from one rule. The Node.js code we run and the rule we removed.
Currency Conversion: Handling Exchange Rates Correctly
Exchange rates change constantly. Learn how to handle currency conversion in applications with accuracy and reliability.
API Rate Limiting Done Right: A Complete Guide
Learn how to design rate limits that protect your API while maintaining good developer experience.
WHOIS Data: Domain Intelligence for Business and Security
WHOIS data reveals domain ownership, age, and infrastructure. Use it for lead qualification, research, and fraud detection.
Email Validation Regex vs Real Addresses: 18 Tests
We ran 18 addresses through three popular email regexes and our own validator. Three of the four rejected a real address, ours included.
How Accurate Is IP Geolocation? We Tested 2,852 IPs
We checked 2,852 RIPE Atlas probes with known locations against our IP lookup. Country: 99.4%. Median error: 13 km. One in five off by 100 km or more.
The Timezone Bug That Cost Us a Client
A scheduled email went out at 3 AM instead of 9 AM. The client wasn't happy. Here's what went wrong.
7 Content Moderation Mistakes That Sink Apps
Your app allows user content. Here are the moderation mistakes that get apps pulled from stores.
Build a Currency Converter in Python with an API
Convert currency in Python with the Exchange Rate API: one GET request, a working CLI converter, error handling, and a repo you can clone. Free key to start.
QR Codes Are Back (And This Time It's Different)
Remember when QR codes were a punchline? Now they're everywhere. Here's why this time it stuck.
What Your User Agent String Reveals
Every HTTP request announces who you are. Here's what's in that string and what you can do with it.
The Phone Number Validation Rabbit Hole
Validating phone numbers seems simple until you try it. Here's what makes it surprisingly complex.
Building Health-Conscious Apps With Air Quality Data
Air quality affects millions of users. Here's how to integrate environmental health data meaningfully.
Automating Visual Testing With Screenshots
Catch visual bugs before users do. Here's how to add screenshot-based testing to your workflow.
Domain Expiration Was Not On Our Alerting Checklist
The domain expired on Saturday. By Monday, competitors bought it. Here's how to avoid this disaster.
Why Your Sentiment Analysis Is Wrong
Sentiment analysis is powerful but often misused. Here's how to use sentiment data effectively.
Attack Surface: The Subdomains You Forgot You Had
Your main site is secure, but what about staging.yourcompany.com? Here's why subdomain discovery matters.
The DNS Migration Checklist Nobody Talks About
DNS propagation takes 24-48 hours. Except when it doesn't. Here's the zero-downtime DNS migration checklist.
Email Deliverability is Not Your Email Server's Problem
Your email server works perfectly but emails go to spam. Here's why IP reputation matters and how to avoid blacklists.
The Developer's Guide to API Vendor Lock-In
Every API integration is a bet. Here's how to recognize lock-in traps before you're stuck, and how to build your way out.
API Latency: Why 200ms Feels Like Forever
Users don't count milliseconds, but they feel them. Here's why API latency matters more than you think, and what to do about it.
What Happens When Your API Provider Shuts Down
The email lands in your inbox: 'Service Discontinuation Notice.' Now what? A guide to surviving API provider shutdowns.
API Documentation: Good, Bad, and Unusable
You can tell everything about an API from its documentation. Here's how to read the signs before you commit to an integration.
The Hidden Cost of Free APIs
Free APIs sound great until they aren't. Here's what that $0 price tag actually costs you in reliability, support, and midnight debugging sessions.
429 Too Many Requests: 2 Meanings and How to Tell
A 429 means slow down, or on many APIs, out of quota. How to tell them apart, a Node.js pacer that avoids them, and why rate limits are never exact.
Why Your API Integration Keeps Breaking
APIs break in production. Here's why it happens and how to build integrations that survive the real world.
API Security Checklist: 15 Pre-Production Checks
A no-fluff checklist of security basics to review before your API integration goes live. Print it, pin it, check it off.
Build vs Buy: When to Use an API Instead
You could build it yourself. But should you? Here's how to decide when an API makes sense and when rolling your own is the right call.
Choosing an API Provider: What Actually Matters
Not all API providers are equal. Here's how to evaluate them before you're locked in and regretting it.
IP Fraud Detection: VPNs, Tor, and Blacklists
Build an IP-based fraud scoring system. Detect VPNs, Tor exit nodes, and blacklisted IPs before they cost you money.
PDF Generation API: Invoices, Reports, Documents
Generate PDFs from HTML or Markdown. Perfect for invoices, receipts, reports, and any document you need to create programmatically.
QR Codes: More Useful Than You Think
URLs, WiFi passwords, contact cards, payment links—QR codes do more than you'd expect. Here's how to generate and read them programmatically.
KYC Verification API: Automate Identity Checks
Build automated KYC checks with email validation, phone verification, IP geolocation, and BIN lookup. Here's the complete implementation.
API Authentication Best Practices in 2026
Stop overthinking auth. API keys for servers, OAuth for users, JWTs for stateless. Here's what actually matters.
Python API Tutorial: Your First APIVerve Call
10 lines of Python. That's all it takes to call 300+ APIs. Here's the complete quickstart for Python developers.
Scalable API Architecture: Monolith to Microservices
Learn how to design and build API architectures that scale with your business, from initial setup to handling millions of requests.
API Caching: The Cheapest Performance Win
Every duplicate API call is wasted money. Here's how to cache responses properly—and when not to.
Retry With Exponential Backoff: 7 Errors, 2 Retries
Which API errors are worth retrying? We ran a Node.js retry client against seven failures and it retried two. The code, and the bugs that shaped it.
REST vs GraphQL: Which Should You Use?
Skip the theory. Here's when to use REST endpoints and when GraphQL actually makes sense.
Add Daily Horoscopes to Your App in 5 Minutes
Build a horoscope feature your users will actually check daily. Working code included.
Build a Lead Enrichment Pipeline That Actually Works
Turn email addresses into full customer profiles. Location, company, social links—automatically. Here's how to build it.
Email Validation That Actually Works
That regex you found on Stack Overflow is wrong. Here's how to validate emails properly—and why it matters more than you think.
Multi-Currency E-commerce: Stop Losing Sales
Showing prices in local currency increases conversions 20-40%. Here's how to implement multi-currency pricing that actually works.
Sentiment Analysis: Read Customer Feedback at Scale
Process thousands of reviews, support tickets, and social mentions automatically. Find the signal in the noise.
Weather APIs: Build a Dashboard That's Actually Useful
Current conditions, forecasts, air quality, sunrise times—here's how to build a weather dashboard users will love.
Content Moderation: Protect Your Platform From UGC
User-generated content is a liability until it's moderated. NSFW detection, profanity filtering, spam detection—here's how to automate it.
Location APIs: Distance, Geocoding, and Timezones
Build location-aware features without Google Maps pricing. Distance calculations, address lookup, timezone handling—all from one API.
Real-Time APIs: WebSockets vs Server-Sent Events
Compare WebSockets and Server-Sent Events for real-time data. Learn when to use each and how to implement them.
Building REST APIs with Node.js and Express
Step-by-step guide to building production-ready REST APIs with Node.js and Express. Routing, middleware, error handling.
Complete Guide to API Testing with Postman
Master API testing with Postman. Learn collections, environments, automated tests, and debugging techniques.
Chuck Norris Jokes API: Add Random Facts to Any App
Add Chuck Norris jokes to your app in under 5 minutes. Real code examples for Slack bots, Discord bots, and loading screens.
Geocoding API Guide: Convert Addresses to Coordinates
Learn how to convert addresses to coordinates and vice versa using geocoding APIs. Practical examples and best practices.
REST APIs: What They Are and How to Use Them
A no-nonsense guide to REST APIs. Learn HTTP methods, make real requests, and stop being confused by API documentation.
Token-Based API Billing: How It Works
Understand how token-based billing works for APIs. Learn credits, usage tracking, and how to optimize your API costs.