---
id: impit-http-client
title: Impit HTTP Client
description: Browser impersonation for HTTP requests using the Impit library
---

import CodeBlock from '@theme/CodeBlock';

import BasicUsageSource from '!!raw-loader!./basic-usage.ts';
import CheerioCrawlerSource from '!!raw-loader!./cheerio-crawler.ts';
import HttpCrawlerSource from '!!raw-loader!./http-crawler.ts';
import AdvancedConfigSource from '!!raw-loader!./advanced-config.ts';

## Introduction

The `ImpitHttpClient` is an HTTP client implementation based on the [Impit](https://github.com/apify/impit) library. It enables browser impersonation for HTTP requests, helping you bypass bot detection systems without running an actual browser.

:::info Successor to got-scraping

Impit is the successor to `got-scraping`, which is no longer actively maintained. We recommend using `ImpitHttpClient` for all new projects. Impit provides better anti-bot evasion through TLS fingerprinting and HTTP/3 support, while maintaining a smaller package size.

**Impit will become the default HTTP client in the next major version of Crawlee.**

:::

### Why use Impit?

Websites increasingly use sophisticated bot detection that analyzes:

- **HTTP fingerprints**: User-Agent strings, header ordering, HTTP/2 pseudo-header sequences
- **TLS fingerprints**: Cipher suites, TLS extensions, and cryptographic details in the ClientHello message

Standard HTTP clients like `fetch` or `axios` are easily detected because their fingerprints don't match real browsers. Unlike `got-scraping` which only handles HTTP-level fingerprinting, Impit also mimics TLS fingerprints, making requests appear to come from real browsers.

## Installation

Install the `@crawlee/impit-client` package:

```bash npm2yarn
npm install @crawlee/impit-client
```

:::note

The `impit` package includes native binaries and supports Windows, macOS (including ARM), and Linux out of the box.

:::

## Basic usage

Pass the `ImpitHttpClient` instance to the `httpClient` option of any Crawlee crawler:

<CodeBlock language="ts">{BasicUsageSource}</CodeBlock>

## Usage with different crawlers

### CheerioCrawler

<CodeBlock language="ts">{CheerioCrawlerSource}</CodeBlock>

### HttpCrawler

<CodeBlock language="ts">{HttpCrawlerSource}</CodeBlock>

## Configuration options

The `ImpitHttpClient` constructor accepts the following options:

| Option | Type | Default | Description |
|--------|------|---------|-------------|
| `browser` | `'chrome'` \| `'firefox'` \| `...` | `undefined` | Browser to impersonate. Affects TLS fingerprint and default headers. |
| `http3` | `boolean` | `false` | Enable HTTP/3 (QUIC) protocol support. |
| `ignoreTlsErrors` | `boolean` | `false` | Ignore TLS certificate errors. Useful for testing or self-signed certificates. |


### Available fingerprints

Impit bundles several realistic browser fingerprints.
Using version-specific fingerprints can improve success rates against sophisticated bot detection systems that track browser versions and flag outdated signatures.

When using generic fingerprints (`chrome` or `firefox`), Impit automatically selects an appropriate version. For most use cases, the generic options are sufficient.
However, if you're targeting a site with particularly strict bot detection, or need to match a specific browser environment, you can specify an exact version:

```ts
import { ImpitHttpClient } from '@crawlee/impit-client';

// Use a generic Chrome fingerprint
const chromeClient = new ImpitHttpClient({ browser: 'chrome' });

// Use a specific Chrome version
const chrome131Client = new ImpitHttpClient({ browser: 'chrome131' });

// Or a specific Firefox version
const firefox144Client = new ImpitHttpClient({ browser: 'firefox144' });
```

### Advanced configuration

<CodeBlock language="ts">{AdvancedConfigSource}</CodeBlock>

## Proxy support

Proxies are configured per-request through Crawlee's proxy management system, not on the `ImpitHttpClient` itself. Use `ProxyConfiguration` as you normally would:

```ts
import { CheerioCrawler, ProxyConfiguration } from 'crawlee';
import { ImpitHttpClient, Browser } from '@crawlee/impit-client';

const proxyConfiguration = new ProxyConfiguration({
    proxyUrls: ['http://proxy1.example.com:8080', 'http://proxy2.example.com:8080'],
});

const crawler = new CheerioCrawler({
    httpClient: new ImpitHttpClient({ browser: Browser.Chrome }),
    proxyConfiguration,
    async requestHandler({ $, request }) {
        console.log(`Scraped ${request.url}`);
    },
});
```

## How it works

Impit achieves browser impersonation at two levels:

1. **HTTP level**: Mimics browser-specific header ordering, HTTP/2 settings, and pseudo-header sequences that antibot services analyze.

2. **TLS level**: Uses a patched version of `rustls` to replicate the exact TLS ClientHello message that browsers send, including cipher suites and extensions.

This dual-layer approach makes requests appear to come from a real browser, significantly reducing blocks from bot detection systems.

## Comparison with other solutions

| Feature | got-scraping | curl-impersonate | Impit |
|---------|--------------|------------------|-------|
| TLS fingerprinting | No | Yes | Yes |
| HTTP/3 support | No | Yes | Yes |
| Native Node.js package | Yes | No (child process) | Yes |
| Windows/macOS ARM | Yes | No | Yes |
| Package size | ~10 MB | ~20 MB | ~8 MB |

**Related links**

- [Impit GitHub repository](https://github.com/apify/impit)
- [Custom HTTP Client guide](./custom-http-client)
- [Proxy Management guide](./proxy-management)
- [Avoiding blocking guide](./avoid-blocking)