---
canonical: 'https://htmlcsstoimage.com/features/url-to-webp/csharp'
title: 'Screenshot Webpages as WebP in C# | HTML/CSS to Image'
description: 'Take webpage screenshots as WebP in C#. Capture a URL with viewport, full-page, selector, and browser controls.'
---

# Take WebP webpage screenshots in C# without managing Chrome

Capture public webpages from C# without installing Chrome, running Playwright or Selenium, or maintaining screenshot storage and delivery.

## Why use the API instead of native C# screenshot automation?

- Keep ASP.NET services and background workers free of local browser binaries and browser-process lifecycle code.
- Set viewport, full-page, selector, timing, color scheme, and browser-state controls as request parameters instead of browser scripts.
- Receive a hosted .webp URL without building a separate pipeline for temporary files, uploads, storage, and delivery.

## Complete C# request

Use this request to capture the example webpage as WebP.

```csharp
using System.Net.Http.Headers;
using System.Net.Http.Json;
using System.Collections.Generic;
using System.Text;
using System.Text.Json.Nodes;

var apiId = Environment.GetEnvironmentVariable("HCTI_API_ID")!;
var apiKey = Environment.GetEnvironmentVariable("HCTI_API_KEY")!;
using var client = new HttpClient();
var credentials = Convert.ToBase64String(Encoding.ASCII.GetBytes($"{apiId}:{apiKey}"));
client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Basic", credentials);

var request = new
{
    url = "https://example.com",
    format = "webp",
    viewport_height = 630,
    viewport_width = 1200,
};

using var response = await client.PostAsJsonAsync("https://hcti.io/v1/image", request);
response.EnsureSuccessStatusCode();
var result = await response.Content.ReadFromJsonAsync<JsonObject>();
var imageUrl = result?["url"]?.GetValue<string>();
if (imageUrl is not null)
{
    Console.WriteLine(imageUrl);
}

```

## When to use WebP

WebP combines modern compression with strong visual quality, making it a good fit for webpage screenshots delivered on the web.

- **Efficient compression**: Deliver high-quality webpage captures with smaller files than many traditional image formats.
- **Transparency support**: Keep transparent page areas while benefiting from a web-focused output format.
- **Built for web delivery**: Use WebP for product previews, content feeds, monitoring dashboards, and performance-sensitive applications.

## API request

Send an authenticated `POST` request to `https://hcti.io/v1/image`. Include `url`, `format`, and any viewport, selector, timing, or browser options required for the capture.

```json
{
  "url": "https://example.com",
  "format": "webp",
  "viewport_width": 1200,
  "viewport_height": 630
}
```

## Request workflow

1. **Send the webpage URL** — Submit a public URL with format set to webp and any viewport, selector, or browser settings.
2. **Chromium loads the page** — The API runs the webpage, styles, fonts, images, and JavaScript in a managed browser environment.
3. **Use the .webp URL** — Embed the hosted result, download the file, or save it in your own storage and application records.

## Capture controls and output handling

- Authenticate from trusted server-side code. Do not expose an API key in browser JavaScript, logs, or agent-visible output.
- Use `full_screen`, `selector`, viewport dimensions, timing, and browser options to capture the required page state.
- Treat the returned URL as the generated `webp` resource. Download it, embed it, or copy it to configured storage as required.

## Use through MCP

An MCP-compatible agent can connect to `https://mcp.hcti.io` with OAuth and use the connected HTML/CSS to Image account instead of handling an API key directly.

Ask the MCP tool to capture the supplied URL as WebP, or specify `format: webp` explicitly in the request.

- [Read the MCP integration documentation](https://docs.htmlcsstoimage.com/integrations/mcp/)

## Related conversions

- [HTML to WebP](https://htmlcsstoimage.com/features/html-to-webp/csharp.md): Render supplied HTML and CSS as WebP instead of capturing a public webpage.
- [URL to PNG](https://htmlcsstoimage.com/features/url-to-png/csharp.md): PNG preserves sharp text, interface details, and transparency, making it a reliable format for webpage archives and UI captures.
- [URL to JPEG](https://htmlcsstoimage.com/features/url-to-jpeg/csharp.md): JPEG is a practical choice for photographic and content-heavy webpages where broad compatibility and smaller files matter.
- [URL to PDF](https://htmlcsstoimage.com/features/url-to-pdf.md): Generate paginated documents from public webpages with page sizing, margins, backgrounds, and print styles.

## Reference links

- [URL screenshot API documentation](https://docs.htmlcsstoimage.com/getting-started/url-to-image/)
- [MCP integration documentation](https://docs.htmlcsstoimage.com/integrations/mcp/)
- [Interactive URL to WebP page](https://htmlcsstoimage.com/features/url-to-webp/csharp)
- [Plans and current limits](https://htmlcsstoimage.com/pricing.md)