Looking for a simpler, faster way to invoke AWS Lambda functions—without the complexity of API Gateway? AWS Lambda URLs, also known as Lambda function URLs, might just be your best-kept secret.

For technology leaders, especially CEOs and CTOs of startups and SMBs, AWS Lambda URLs provide a lean way to move faster, reduce infrastructure complexity, and cut unnecessary costs.

In this guide, you’ll learn how Lambda URLs work, when to use them, and why they’re a smart shortcut for building nimble serverless apps.

What is Lambda function URL?

A Lambda function URL is a built-in HTTPS endpoint that lets you trigger an AWS Lambda function directly—no API Gateway required. It’s ideal for fast prototyping, long-running tasks, or lightweight public endpoints.

Watch explanation of AWS Lambda URL in under 5 minutes at our Perfsys Youtube Channel: AWS Lambda URLs: A Simpler Way to Build Serverless APIs Without API Gateway

Table of Contents

• Why API Gateway Can Be Overkill
• What Exactly Is a Lambda Function URL?
• Top Benefits of Using Lambda URLs
• Limitations to Be Aware Of
• Best Use Cases for Lambda URLs
• Lambda Function URL vs API Gateway
• Related Questions
• Further Reading
• TL;DR Summary

Why API Gateway Can Be Overkill

Do you really need a full-blown API Gateway setup for every Lambda function? Not always.

While API Gateway is powerful—supporting features like request validation, caching, and throttling—it’s also time-consuming and costly for simpler workloads. Developers often spend hours setting up routes, methods, and permissions. On top of that, API Gateway defaults to a 1-minute timeout, which can be a blocker for long-running processes.

By contrast, AWS Lambda URLs allow you to bypass all of this. You get a direct HTTPS endpoint tied to your Lambda function with just a few clicks. For lean startups and SMBs where speed-to-market is crucial, Lambda URLs provide a smarter alternative.

What Exactly Is a Lambda Function URL?

An AWS Lambda URL (or Lambda function URL) is a native HTTPS endpoint attached to your Lambda function. Once enabled, it allows you to:

• Invoke the Lambda directly via HTTP requests
• Skip API Gateway configuration
• Reduce cost and infrastructure overhead

For example, instead of configuring an entire API stack just to process a webhook from Stripe or GitHub, you can simply enable a Lambda URL and get a secure endpoint immediately.

It’s as straightforward as hitting a Lambda function URL in your browser or from an application and having AWS Lambda execute your business logic.

Top Benefits of Using Lambda URLs

Here’s why more teams are adopting Lambda URLs over API Gateway:

• No API Gateway required – drastically simplifies architecture
• Supports long-running tasks – up to 15 minutes
• Ideal for webhooks & lightweight endpoints
• Great for MVPs, internal dashboards, or proof-of-concept tools

Learn more about how to build your MVP on AWS

Limitations to Be Aware Of

AWS Lambda URLs are intentionally lightweight. That means they don’t include every feature you’d get with a full API Gateway setup:

• No built-in authentication beyond IAM (though IAM signatures can protect your endpoints)
• No request mapping, rate limiting, or caching
• No custom domain names unless you configure them through Route 53 or CloudFront
• Less control over routing, since Lambda URLs act as a single entry point to one function

If your project needs advanced features, you can understand API Gateway in depth to evaluate the right fit.

Best Use Cases for Lambda URLs

Lambda URLs shine in scenarios where speed and simplicity matter most:

• Receiving public webhooks from third-party tools
• Launching a background job or scheduled task
• Building a quick proof of concept or MVP
• Serving internal tools where security is handled upstream

Lambda Function URL vs API Gateway

What’s the difference between a Lambda function URL and API Gateway?

Feature Comparison Table

Feature	Lambda Function URL	API Gateway
Setup Complexity	Minimal	Moderate to High
Authentication	Basic (IAM)	Advanced (Cognito, OAuth, etc.)
Request/Response Mapping	None	Full Support
Timeout	15 minutes	1 minute (default)
Best For	Webhooks, MVPs, internal tools	Full-featured APIs

FAQ

How do Lambda function URLs differ from API Gateway endpoints?

Lambda function URLs are direct-to-function triggers that bypass API Gateway’s complex setup—making them faster to implement but more limited in features.

Can you secure a Lambda function URL?

Yes, with IAM-based signature authentication, though there’s no built-in token or OAuth support like API Gateway offers.

Is performance impacted when using Lambda function URLs?

They are efficient for small to medium workloads, but lack built-in caching or throttling options.

Further Reading

Want a deeper breakdown of Lambda function URL vs API Gateway?
Read about API Gateway on our blog

TL;DR Summary

• Lambda function URLs are direct HTTPS endpoints to invoke Lambda.
• Perfect for MVPs, internal tools, and public webhooks.
• Skip API Gateway setup for simpler, faster development.
• Not ideal for complex apps requiring advanced auth or routing.

FAQ