Solve UI Testing Problems: Replay AI Creates Testable Code from UI Videos (2026)

TL;DR: Replay leverages AI to reconstruct testable UI code directly from screen recordings, enabling faster and more reliable UI testing workflows.

Solve UI Testing Problems: Replay AI Creates Testable Code from UI Videos (2026)#

UI testing is a persistent headache for developers. Traditional methods are slow, brittle, and often fail to catch subtle regressions. Manually writing UI tests is time-consuming, and relying on screenshot-based tools misses the crucial context of user behavior. What if you could generate robust, testable UI code directly from video recordings of user interactions? That's the promise of Replay.

Replay utilizes a revolutionary approach: Behavior-Driven Reconstruction. Instead of simply capturing visual elements, Replay analyzes video to understand the intent behind user actions, reconstructing a functional UI along with the code necessary for comprehensive testing.

The Problem with Traditional UI Testing#

Let's face it, traditional UI testing is a pain. Here's why:

• •Manual Test Creation: Writing UI tests by hand is tedious and error-prone.
• •Brittleness: Tests break easily with minor UI changes, requiring constant maintenance.
• •Limited Coverage: It's difficult to anticipate all possible user interactions and create tests for them.
• •Screenshot-Based Limitations: Tools that rely on screenshots only capture the visual state, missing the dynamic aspects of user behavior.
• •Time-Consuming Debugging: Identifying the root cause of UI failures can be a slow and frustrating process.

Replay: A New Approach to UI Testing#

Replay offers a paradigm shift in UI testing by analyzing video recordings of user interactions and generating testable UI code. This approach addresses the limitations of traditional methods and offers several key advantages:

• •Automated Test Generation: Replay automatically generates UI code and corresponding tests from video recordings.
• •Behavior-Driven Reconstruction: Replay understands user intent, resulting in more robust and reliable tests.
• •Reduced Maintenance: Tests are less likely to break due to minor UI changes because they are based on behavior, not just visual appearance.
• •Improved Coverage: Easily capture a wide range of user interactions and generate tests for them.
• •Faster Debugging: Replay provides detailed insights into user behavior, making it easier to identify and fix UI issues.

How Replay Works: Behavior-Driven Reconstruction#

Replay's core innovation is its ability to understand user behavior from video. It doesn't just see pixels; it understands actions, flows, and intent. This is achieved through a combination of advanced video analysis, machine learning, and the power of Gemini.

Here's a simplified breakdown of the process:

1. •Video Capture: Record a video of a user interacting with your UI. This could be a user testing session, a demo, or even just you using the application.
2. •Video Analysis: Replay analyzes the video, identifying UI elements, user actions (clicks, scrolls, typing), and the sequence of events.
3. •Intent Inference: Using advanced machine learning models, Replay infers the user's intent behind each action. For example, it can distinguish between a click intended to open a menu and a click intended to submit a form.
4. •Code Generation: Replay generates clean, functional UI code (e.g., React, Vue, Angular) based on the reconstructed UI and the inferred user behavior. This code includes the necessary event handlers and data bindings to replicate the user's interactions.
5. •Test Generation: Replay automatically generates UI tests (e.g., using Jest, Cypress, Playwright) that verify the correctness of the generated code and the intended user behavior.

Key Features of Replay#

• •Multi-Page Generation: Replay can reconstruct UIs that span multiple pages, capturing complex user flows.
• •Supabase Integration: Seamlessly integrate with your Supabase backend for data persistence and real-time updates.
• •Style Injection: Replay accurately captures and applies CSS styles, ensuring visual fidelity.
• •Product Flow Maps: Visualize user flows and identify potential bottlenecks in your UI.

Replay vs. Traditional UI Testing Tools#

Example: Generating a Simple Login Form#

Let's say you have a simple login form. Here's how you can use Replay to generate the UI code and tests:

1. •Record a video: Record yourself filling out the login form, clicking the submit button, and verifying that you are redirected to the dashboard.
2. •Upload the video to Replay: Replay will analyze the video and reconstruct the UI.
3. •Review and refine the generated code: Replay provides a user-friendly interface for reviewing and refining the generated code.
4. •Generate tests: Replay automatically generates UI tests that verify the login functionality.

Here's an example of the generated React code:

typescript
// Generated by Replay
import React, { useState } from 'react';

const LoginForm = () => {
  const [username, setUsername] = useState('');
  const [password, setPassword] = useState('');

  const handleSubmit = async (e: React.FormEvent) => {
    e.preventDefault();
    // Simulate API call
    const response = await fetch('/api/login', {
      method: 'POST',
      body: JSON.stringify({ username, password }),
      headers: {
        'Content-Type': 'application/json',
      },
    });

    if (response.ok) {
      window.location.href = '/dashboard';
    } else {
      alert('Invalid credentials');
    }
  };

  return (
    <form onSubmit={handleSubmit}>
      <label>
        Username:
        <input
          type="text"
          value={username}
          onChange={(e) => setUsername(e.target.value)}
        />
      </label>
      <label>
        Password:
        <input
          type="password"
          value={password}
          onChange={(e) => setPassword(e.target.value)}
        />
      </label>
      <button type="submit">Login</button>
    </form>
  );
};

export default LoginForm;

And here's an example of a generated Jest test:

javascript
// Generated by Replay
import React from 'react';
import { render, screen, fireEvent } from '@testing-library/react';
import LoginForm from './LoginForm';

describe('LoginForm', () => {
  it('submits the form with valid credentials', async () => {
    // Mock the API call
    global.fetch = jest.fn(() =>
      Promise.resolve({
        ok: true,
      })
    );

    render(<LoginForm />);

    const usernameInput = screen.getByLabelText('Username:');
    const passwordInput = screen.getByLabelText('Password:');
    const submitButton = screen.getByText('Login');

    fireEvent.change(usernameInput, { target: { value: 'testuser' } });
    fireEvent.change(passwordInput, { target: { value: 'password' } });
    fireEvent.click(submitButton);

    expect(fetch).toHaveBeenCalledWith(
      '/api/login',
      expect.objectContaining({
        method: 'POST',
        body: JSON.stringify({ username: 'testuser', password: 'password' }),
      })
    );
  });
});

💡 Pro Tip: Replay excels at reconstructing complex UI flows, such as multi-step forms, e-commerce checkouts, and interactive dashboards. Capture the entire flow in a single video for best results.

Step-by-Step Guide: Generating a Product Page with Replay#

Let's walk through a more detailed example: generating a product page for an e-commerce site.

Step 1: Record the User Interaction#

Use a screen recording tool to capture the following interaction:

1. •Navigate to the product page.
2. •View the product details (image, description, price).
3. •Select a size and color (if applicable).
4. •Add the product to the cart.

Step 2: Upload to Replay#

Upload the recorded video to Replay. Replay will begin analyzing the video and reconstructing the UI.

Step 3: Review and Refine#

Once the reconstruction is complete, review the generated code and UI. You can make adjustments to the code, styles, and data bindings as needed. Replay provides a visual editor that allows you to fine-tune the UI.

Step 4: Generate Tests#

Click the "Generate Tests" button. Replay will automatically generate UI tests that verify the functionality of the product page, including:

• •Displaying product details correctly.
• •Allowing users to select options (size, color).
• •Adding the product to the cart.

Step 5: Integrate and Deploy#

Integrate the generated code and tests into your existing codebase. Deploy the changes to your production environment.

📝 Note: Replay supports various UI frameworks, including React, Vue, and Angular. Choose the framework that best suits your needs.

Advanced Use Cases#

Replay is not just for basic UI testing. It can also be used for:

• •Regression Testing: Quickly identify UI regressions by comparing video recordings of different versions of your application.
• •A/B Testing: Generate UI variations from video recordings and test their performance.
• •User Interface Documentation: Automatically generate UI documentation from video recordings of user interactions.
• •Onboarding Flows: Create interactive onboarding flows by capturing video recordings of users learning how to use your application.

⚠️ Warning: While Replay significantly reduces manual effort, it's crucial to review and refine the generated code and tests to ensure accuracy and completeness.

Benefits of Using Replay#

• •Faster Development Cycles: Automate UI testing and reduce the time spent on manual testing.
• •Improved Code Quality: Generate clean, functional UI code that is easy to maintain.
• •Reduced Maintenance Costs: Tests are less likely to break due to minor UI changes.
• •Enhanced User Experience: Identify and fix UI issues early in the development process.
• •Comprehensive Test Coverage: Easily capture a wide range of user interactions and generate tests for them.

Frequently Asked Questions#

Is Replay free to use?#

Replay offers a free tier with limited features. Paid plans are available for more advanced functionality and higher usage limits. Check the pricing page on our website for the most up-to-date information.

How is Replay different from v0.dev?#

While both Replay and v0.dev aim to accelerate UI development, they take fundamentally different approaches. V0.dev generates code from text prompts, while Replay generates code and tests from video recordings of user interactions. Replay understands behavior by analyzing video, leading to more robust and maintainable code. Replay emphasizes behavior-driven reconstruction, making it uniquely suited for UI testing and capturing complex user flows.

What UI frameworks does Replay support?#

Replay currently supports React, Vue, and Angular. We are actively working on adding support for other frameworks.

How accurate is Replay's code generation?#

Replay's code generation is highly accurate, but it's always recommended to review and refine the generated code to ensure it meets your specific requirements.

How does Replay handle dynamic data?#

Replay can handle dynamic data by integrating with your backend API. You can provide Replay with sample data to use during the code generation process.

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