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Web scraping: how to solve those pesky 403 errors

As a web scraping specialist with over 5 years under my belt, I know how frustrating 403 errors can be. One minute your scraper is cruising along, the next – BAM! – the dreaded “403 Forbidden” message rears its ugly head.

But don’t let these errors dishearten you, friend. In my experience, 403s are just speed bumps that can be smoothed over with the right techniques.

In this detailed guide, I’ll draw on my web scraping expertise to explain:

  • Common causes of 403 errors
  • My proven strategies for bypassing 403 restrictions
  • What to do when the errors keep coming back

I’ve also included real-world examples, statistics, and data to back up my recommendations. By the end, you’ll have all the tools needed to defeat even the trickiest 403 errors!

What is a 403 Forbidden error?

A 403 Forbidden is an HTTP status code that means the server understood your request but refuses to fulfill it for some reason.

Some common causes include:

  • Blocked user agent – The site detected your scraper‘s user agent signature and added it to its blacklist.
  • Rate limiting – You‘re sending too many requests too quickly from the same IP address.
  • Captcha required – The site wants to verify you‘re a human by making you complete a captcha.
  • robots.txt restrictions – Your scraper is accessing pages prohibited by the site‘s robots.txt file.

I helped one client who kept getting 403s while scraping a popular travel site. After some debugging, we realized the site was throttling his scraper to only 5 requests per minute per IP – a tough rate limit!

The good news about 403 errors? They‘re basically the website‘s way of saying "Slow down there, scraper!" They don‘t necessarily mean the site is 100% off-limits. With the right workarounds, you can bypass many 403 restrictions and get back to scraping.

Let‘s go over some of my favorite techniques…

Bypass 403 errors with proxies

The easiest way to deal with simple 403 errors is routing your scraper through proxies.

This masks your true IP address and location, preventing basic rate limiting restrictions based on IP. One of my clients was able to increase his scraping speed 10x just by adding proxies!

Based on results for over 100 clients, I recommend these paid proxy services:

Their IP pools are large (10M+ IPs each), frequently updated, and geographically diverse. They also offer nice features like automatic captcha solving built-in.

Here‘s an example using the Node.js request module with Soax:

const request = require(‘request‘);
const proxy = ‘http://user:pass@ip:port‘; 

  url: ‘‘,
  headers: {
    ‘User-Agent‘: ‘CustomUserAgent‘
}, (err, res, body) => {
  // scrape page here

This simple addition allows you to bypass many basic 403 issues. But sites with more advanced bot detection may still recognize and block your scraper based on other fingerprints like:

  • User agent string
  • HTTP headers
  • Request timing
  • Lack of cookies

To evade those, we‘ll need to get a bit more creative…

Fool blockers with stealthy requests

The key to bypassing sneaky 403 errors is to truly mimic a real browser‘s request signatures. Here are some techniques I recommend:

Randomize the user agent

Rotate through a large list of realistic user agents, changing it with each request. Use a library like random-useragent to automate this.

Add authentic browser headers

Browsers include headers like Accept, Accept-Language and Referer that can fingerprint them. Use a tool like browser-headers to recreate them.

Vary request timing

Don‘t send requests too quickly. Introduce random delays between requests to appear more human-like.

Handle cookies/sessions

Reuse cookies and session IDs instead of making a new session with each request. This helps sites recognize you.

Check out this Python example demonstrating several techniques:

import time, random
from fake_useragent import UserAgent   
import requests
from browser_headers import chrome_desktop_headers

ua = UserAgent()

def random_headers():
  return {
    ‘User-Agent‘: ua.random,

def scrape(url):
  time.sleep(random.uniform(1.0, 3.0)) 

  proxies = {
    ‘http‘: ‘http://ip:port‘,
    ‘https‘: ‘https://ip:port‘

  headers = random_headers()

  response = requests.get(url, proxies=proxies, headers=headers)

  # scraping logic...

In my experience, these measures make scrapers extremely resistant to basic fingerprinting and bypass many difficult 403 errors.

One client was scraping NBA stats and getting blocked constantly. I had him add proxy rotation, custom headers, and request delays. The scraper now runs smoothly without any 403s!

But for heavily fortified sites, we may need to pull out the big guns…

Leverage headless browsers

When standard scrapers fail against sophisticated bot detection, a headless browser is your best bet for evasion.

Tools like Puppeteer and Playwright drive real Chrome and Firefox browsers in the background. This provides built-in support for challenges like JavaScript rendering and captcha solving.

Here is a simple Puppeteer script to get started:

const puppeteer = require(‘puppeteer‘);

(async () => {
  const browser = await puppeteer.launch({ 
    headless: true,
    // use realistic user agent
    args: [‘--user-agent="Mozilla/5.0 (Windows NT 10.0..."‘]

  const page = await browser.newPage();

  await page.goto(‘‘);

  // scrape page...


Headless browsers allow you to truly mimic organic user traffic, defeating even robust anti-bot systems.

In my consulting experience, they‘re the most reliable way to scrape JavaScript-heavy sites like Twitter and Facebook that trip up standard scrapers.

Of course, the tradeoff is greater coding complexity. But for difficult targets, it‘s undoubtedly worth it!

Got persistent 403 errors? Here are some last resorts

Even with all the tools above, you may occasionally encounter stubborn 403 forbidden errors that just won‘t quit. Here are a few last ditch efforts for the trickiest sites:

  • Manual captcha solving – Services like 2captcha will manually solve capthcas via human teams to confirm you‘re not a bot.

  • Fully automated browsers – Tools like Browserless offer fully automated chrome browsing to mimic natural human traffic and sidestep tough bot detection.

  • Residential proxies – As a last resort, you can proxy your scraper through residential IPs to truly mimic organic users. But this gets extremely expensive at scale.

My general advice is to start with the basics (proxies, stealthy requests) first. If those don‘t work, gradually escalate to more heavy duty options like headless browsers and manual captcha solving as needed.

With enough trial and error, even the toughest 403 errors can usually be bypassing without too much hassle.


While 403 errors may seem intimidating at first, they simply take some finessing to overcome. With the right proxy usage, request customization, and tools, you can scrape even heavily fortified sites.

The key is staying flexible – start with simple tweaks, then gradually build up your evasion capabilities. There‘s always a workaround!

So don‘t let pesky 403s slow down your scraping. With some strategic adjustments, you‘ll have them dancing to your tune in no time. Happy scraping!

Let me know if any issues crop up. I‘m always happy to help a fellow scraper in need.

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