Browser Rendering

Overview

The /browser endpoint fetches a URL with full JavaScript rendering. Unlike /fetch (which returns the raw HTTP response), /browser waits for dynamic content and returns the fully rendered page. When to use /browser instead of /fetch:

The page requires JavaScript to load content (SPAs, dynamic sites)
You need all cookies, including those set by client-side scripts
You want to execute custom JavaScript to extract data
You need a screenshot of the rendered page

The response format is the same as /fetch (meta, raw, raw_json), with additional fields for cookies, screenshots, and JS evaluation results.

Endpoint

GET https://scraping-api.55-tech.com/browser

Works just like /fetch — all parameters are passed via headers.

Request headers

Header	Required	Default	Description
`X-API-Key`	Yes	—	Your API key
`X-Target-URL`	Yes	—	Target URL to render
`X-Wait-Strategy`	No	`load`	`load`, `networkidle`, or `selector` (details)
`X-Wait-Selector`	No	—	CSS selector to wait for (with `selector` strategy)
`X-Timeout`	No	`30`	Timeout in seconds (max 300 for `/browser`)
`X-JS-Expression`	No	—	JavaScript to evaluate after the page is ready
`X-Screenshot`	No	`false`	Capture screenshot (`1` or `true`)
`X-Expect-Selector`	No	—	CSS selector that must exist — retries on a different node if missing
`X-Expect-Contains`	No	—	Substring that must exist in the body — retries if missing
`X-Proxy`	No	—	Route through a proxy (`http://` or `socks5://`)
`X-Steps`	No	—	JSON array of sequential browser actions (details)
`X-Block-Resources`	No	—	Comma-separated resource types to block: `image,font,stylesheet,media`. No default blocking
`X-Geo`	No	—	Country filter for node selection (e.g. `US`, `DE,AT`)
`X-Agent`	No	—	Pin to a specific node (e.g. `de1`, `us3`)
`Cookie`	No	—	Cookies to inject (`name=value; name2=value2`)
`X-Cookies`	No	—	Cookies as JSON array for full control (format)

Wait strategies

Strategy	Description
`load`	Wait for `DOMContentLoaded` event (fastest, works for server-rendered pages)
`networkidle`	Wait until there are no more than 2 network connections for 500ms (best for SPAs)
`selector`	Wait for `X-Wait-Selector` to appear in the DOM (most precise for specific content)

Cookies

Simple cookies — use the standard Cookie header:

Cookie: session=abc123; token=xyz

Full cookie objects — use the X-Cookies header with a JSON array when you need domain, path, or httpOnly control:

X-Cookies: [{"name":"session","value":"abc","domain":".example.com","secure":true}]

Cookie object fields: name, value, domain, path, secure, httpOnly, sameSite, expires.

Steps

Execute sequential browser actions after the page loads — login flows, multi-page navigation, form filling, clicking through to specific content. Pass a JSON array via the X-Steps header:

X-Steps: [{"action":"type","selector":"#email","value":"user@example.com"},{"action":"click","selector":"#submit"},{"action":"waitNavigation"}]

Available actions:

Action	Params	Description
`navigate`	`url`, `waitUntil`	Navigate to a new URL
`click`	`selector`	Click an element (human-like mouse movement)
`type`	`selector`, `value`, `delay`	Type text into an input (auto-clears first)
`clear`	`selector`	Clear an input field
`select`	`selector`, `value`	Select a dropdown option by value
`wait`	`selector`, `timeout`	Wait for an element to appear
`waitNavigation`	`waitUntil`	Wait for page navigation to complete
`waitHidden`	`selector`	Wait for an element to disappear
`scroll`	`selector` or `x`, `y`	Scroll to an element or by pixels
`hover`	`selector`	Hover over an element
`press`	`key`	Press a keyboard key (`Enter`, `Tab`, `Escape`)
`focus`	`selector`	Focus an element
`evaluate`	`expression`	Run JavaScript in the page
`screenshot`	`fullPage`	Capture a screenshot (returned in step result)
`sleep`	`ms`	Wait a fixed number of milliseconds

Each step runs after the previous completes. Add "continueOnError": true to a step to keep going if it fails. Example: Login → navigate → capture

curl -H "X-API-Key: YOUR_API_KEY" \
  -H "X-Target-URL: https://example.com/login" \
  -H 'X-Steps: [
    {"action": "wait", "selector": "#login-form"},
    {"action": "type", "selector": "#email", "value": "user@example.com"},
    {"action": "type", "selector": "#password", "value": "secret"},
    {"action": "click", "selector": "#submit"},
    {"action": "waitNavigation"},
    {"action": "navigate", "url": "https://example.com/dashboard"},
    {"action": "wait", "selector": ".data-table"}
  ]' \
  -H "X-Timeout: 120" \
  https://scraping-api.55-tech.com/browser

Example: Login then stream live data

curl -N -H "X-API-Key: YOUR_API_KEY" \
  -H "X-Target-URL: https://example.com/login" \
  -H "X-Capture: ws,network" \
  -H 'X-Steps: [
    {"action": "type", "selector": "#email", "value": "user@example.com"},
    {"action": "type", "selector": "#password", "value": "secret"},
    {"action": "click", "selector": "#submit"},
    {"action": "waitNavigation"},
    {"action": "navigate", "url": "https://example.com/live-feed"},
    {"action": "wait", "selector": ".feed-container"}
  ]' \
  https://scraping-api.55-tech.com/browser/stream

Steps work on both /browser (capture after all steps complete) and /browser/stream (stream during and after steps — step results arrive as step_ok / step_error events).

Resource blocking

Block specific resource types to speed up rendering:

X-Block-Resources: image,font,stylesheet

Blocking images and fonts can reduce render time by 50%+ on media-heavy pages.

Response

{
  "meta": {
    "status": 200,
    "final_url": "https://example.com/",
    "http_version": "",
    "elapsed_ms": 3200,
    "blocked": false,
    "headers": { "content-type": "text/html; charset=utf-8" },
    "agent": { "id": "scraping-de5" },
    "bytes": 45210
  },
  "raw": "<!DOCTYPE html><html>...</html>",
  "raw_json": null,
  "cookies": [
    {
      "name": "session_id",
      "value": "a1b2c3...",
      "domain": ".example.com",
      "path": "/",
      "secure": true,
      "httpOnly": true,
      "sameSite": "Lax",
      "expires": 1735689600
    }
  ],
  "screenshot": null,
  "js_result": null
}

Field	Description
`meta`	Same as `/fetch` — status, final URL, headers, timing, node ID
`raw`	Rendered page body as text (HTML or other). `null` if body was valid JSON
`raw_json`	Parsed JSON object if the response was valid JSON, otherwise `null`
`cookies`	All cookies set during rendering, including `httpOnly` cookies
`screenshot`	Base64-encoded PNG of the full page (`null` if not requested)
`js_result`	Return value of `X-JS-Expression` (`null` if not provided)

Response validation

Use X-Expect-Selector and X-Expect-Contains to verify the rendered page has the content you expect. If validation fails, the API automatically retries on a different node before returning an error.

Examples

Render a JavaScript-heavy page

curl -H "X-API-Key: YOUR_API_KEY" \
  -H "X-Target-URL: https://example.com" \
  -H "X-Wait-Strategy: networkidle" \
  https://scraping-api.55-tech.com/browser

Wait for specific content

curl -H "X-API-Key: YOUR_API_KEY" \
  -H "X-Target-URL: https://example.com/dashboard" \
  -H "X-Wait-Strategy: selector" \
  -H "X-Wait-Selector: #data-table" \
  -H "X-Timeout: 45" \
  https://scraping-api.55-tech.com/browser

Extract data with JavaScript

curl -H "X-API-Key: YOUR_API_KEY" \
  -H "X-Target-URL: https://example.com" \
  -H "X-Wait-Strategy: networkidle" \
  -H "X-JS-Expression: JSON.stringify({title: document.title, links: document.querySelectorAll('a').length})" \
  https://scraping-api.55-tech.com/browser

The js_result field in the response contains the return value:

{
  "js_result": "{\"title\":\"Example\",\"links\":42}"
}

Capture a screenshot

curl -H "X-API-Key: YOUR_API_KEY" \
  -H "X-Target-URL: https://example.com" \
  -H "X-Screenshot: 1" \
  -H "X-Block-Resources: image,font" \
  https://scraping-api.55-tech.com/browser

With cookies

curl -H "X-API-Key: YOUR_API_KEY" \
  -H "X-Target-URL: https://example.com" \
  -H "Cookie: session=abc123; token=xyz" \
  -H "X-Wait-Strategy: networkidle" \
  https://scraping-api.55-tech.com/browser

Route through a proxy

curl -H "X-API-Key: YOUR_API_KEY" \
  -H "X-Target-URL: https://geo-restricted-site.com" \
  -H "X-Proxy: http://user:pass@proxy.example.com:8080" \
  -H "X-Geo: US" \
  https://scraping-api.55-tech.com/browser

Validate response content

If the page doesn’t contain the expected content, the API retries on a different node:

curl -H "X-API-Key: YOUR_API_KEY" \
  -H "X-Target-URL: https://example.com/products" \
  -H "X-Wait-Strategy: selector" \
  -H "X-Wait-Selector: .product-list" \
  -H "X-Expect-Selector: .product-list" \
  -H "X-Expect-Contains: price" \
  https://scraping-api.55-tech.com/browser

Python

import requests

resp = requests.get("https://scraping-api.55-tech.com/browser", headers={
    "X-API-Key": "YOUR_API_KEY",
    "X-Target-URL": "https://example.com",
    "X-Wait-Strategy": "networkidle",
    "X-JS-Expression": "document.title",
    "X-Block-Resources": "image,font",
})

data = resp.json()
print(data["meta"]["status"])       # 200
print(data["raw"][:200])            # rendered HTML
print(data["js_result"])            # "Example Domain"

for c in data["cookies"]:
    print(f"{c['name']}={c['value']} (httpOnly={c['httpOnly']})")

JavaScript

const resp = await fetch("https://scraping-api.55-tech.com/browser", {
  headers: {
    "X-API-Key": "YOUR_API_KEY",
    "X-Target-URL": "https://example.com",
    "X-Wait-Strategy": "networkidle",
    "X-JS-Expression": "document.title",
  },
});

const data = await resp.json();
console.log(data.meta.status);       // 200
console.log(data.raw.slice(0, 200)); // rendered HTML
console.log(data.js_result);         // "Example Domain"
console.log(data.cookies.length);    // number of cookies captured

Browser Stream (SSE)

For live, long-running sessions, use /browser/stream. Instead of capturing a single snapshot, the browser stays open and streams events in real-time via Server-Sent Events. Only data-carrying requests (XHR/Fetch API calls) are captured — full HTML pages and JavaScript bundles are filtered out. No resources are blocked by default so pages load fully and widgets initialize correctly. Default wait strategy is networkidle. All data is gzip-compressed. Use cases:

Capture WebSocket frames that the page receives (live data feeds)
Monitor XHR/Fetch API calls the page makes (the actual data endpoints)
Watch DOM elements for changes (price updates, content changes)

Endpoint

GET https://scraping-api.55-tech.com/browser/stream

Headers

Same headers as /browser, with different defaults: X-Wait-Strategy defaults to networkidle, X-Timeout defaults to 0 (runs until disconnect, 24h safety cap), no resource blocking. Plus:

Header	Default	Description
`X-Capture`	`network,ws,console`	Comma-separated event types to stream
`X-DOM-Selector`	—	CSS selector to watch for DOM mutations (requires `dom` in capture)
`X-Network-Filter`	—	Regex filter for network URLs (only matching are streamed)
`X-WS-Filter`	—	Regex filter for WebSocket URLs (only matching are streamed)
`X-JS-After-Load`	—	JavaScript to execute after page load (e.g. click a button, trigger navigation)

SSE events

Event	Description
`connected`	Browser loaded, streaming started (includes cookies)
`network`	HTTP response captured (XHR/Fetch) — includes body, status, content-type
`ws_open`	Page opened a WebSocket connection
`ws_message`	WebSocket frame received by the page
`ws_close`	Page WebSocket closed
`dom`	DOM mutation on watched selector
`console`	Console output (warn/error)
`error`	Error, stream ends
`done`	Session ended (timeout, if set, or client disconnect)

Example: Capture page WebSocket feed

curl -N -H "X-API-Key: YOUR_API_KEY" \
  -H "X-Target-URL: https://example.com/live" \
  -H "X-Capture: ws" \
  -H "X-Timeout: 120" \
  https://scraping-api.55-tech.com/browser/stream

{
  "type": "connected",
  "url": "https://example.com/live",
  "status": 200,
  "agent_id": "scraping-us5",
  "data": "{\"title\":\"Live Feed\",\"cookies\":[{\"name\":\"session\",\"value\":\"abc\"}]}",
  "timestamp": 1775511253069
}

The SSE stream runs until you disconnect. Each event arrives as event: type\ndata: json\n\n. Use curl -N (no buffering) to see events in real-time.

Example: Monitor network API calls

curl -N -H "X-API-Key: YOUR_API_KEY" \
  -H "X-Target-URL: https://example.com/dashboard" \
  -H "X-Capture: network" \
  -H "X-Network-Filter: api\\.example\\.com" \
  https://scraping-api.55-tech.com/browser/stream

Example: Watch DOM element for changes

curl -N -H "X-API-Key: YOUR_API_KEY" \
  -H "X-Target-URL: https://example.com/prices" \
  -H "X-Capture: dom" \
  -H "X-DOM-Selector: #price-table" \
  -H "X-Wait-Strategy: selector" \
  -H "X-Wait-Selector: #price-table" \
  https://scraping-api.55-tech.com/browser/stream

Python

import requests
import json

resp = requests.get("https://scraping-api.55-tech.com/browser/stream", headers={
    "X-API-Key": "YOUR_API_KEY",
    "X-Target-URL": "https://example.com/live",
    "X-Capture": "ws",
}, stream=True)

for line in resp.iter_lines():
    if line.startswith(b"data: "):
        event = json.loads(line[6:])
        if event["type"] == "ws_message":
            print(event["data"])

Next steps

HTTP Fetch

For pages that don’t need JavaScript rendering, use the faster /fetch endpoint.

Error handling

Status codes, block detection, and retry strategies.

Getting Started

Reference

Overview

Endpoint

Request headers

Wait strategies

Cookies

Steps

Resource blocking

Response

Response validation

Examples

Render a JavaScript-heavy page

Wait for specific content

Extract data with JavaScript

Capture a screenshot

With cookies

Route through a proxy

Validate response content

Python

JavaScript

Browser Stream (SSE)

Endpoint

Headers

SSE events

Example: Capture page WebSocket feed

Example: Monitor network API calls

Example: Watch DOM element for changes

Python

Next steps

HTTP Fetch

Error handling

Getting Started

Reference

Documentation Index

​Overview

​Endpoint

​Request headers

​Wait strategies

​Cookies

​Steps

​Resource blocking

​Response

​Response validation

​Examples

​Render a JavaScript-heavy page

​Wait for specific content

​Extract data with JavaScript

​Capture a screenshot

​With cookies

​Route through a proxy

​Validate response content

​Python

​JavaScript

​Browser Stream (SSE)

​Endpoint

​Headers

​SSE events

​Example: Capture page WebSocket feed

​Example: Monitor network API calls

​Example: Watch DOM element for changes

​Python

​Next steps

HTTP Fetch

Error handling

Overview

Endpoint

Request headers

Wait strategies

Cookies

Steps

Resource blocking

Response

Response validation

Examples

Render a JavaScript-heavy page

Wait for specific content

Extract data with JavaScript

Capture a screenshot

With cookies

Route through a proxy

Validate response content

Python

JavaScript

Browser Stream (SSE)

Endpoint

Headers

SSE events

Example: Capture page WebSocket feed

Example: Monitor network API calls

Example: Watch DOM element for changes

Python

Next steps