🧠 Handling CAPTCHAs and File Uploads in Selenium (Advanced Techniques)

When automating web tasks with Selenium, two common challenges arise:

CAPTCHAs – used to block bots.

File uploads – can vary in complexity depending on how the upload UI is implemented.

Let’s tackle each with advanced, real-world strategies.

🔐 Part 1: Handling CAPTCHAs in Selenium

⚠️ Disclaimer:

CAPTCHAs are designed to block automation. Bypassing them may violate site terms of service. Use responsibly and ethically.

✅ Strategy 1: Avoid CAPTCHA Pages

Automate behind a login or API where CAPTCHA isn’t shown.

Use trusted IPs or a valid session cookie to avoid CAPTCHA triggering.

🤖 Strategy 2: Manual CAPTCHA Solving

Allow a human to solve the CAPTCHA during automation.

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# Open page with CAPTCHA

driver.get("https://example.com/captcha-page")

# Wait for user to solve it

input("Solve the CAPTCHA manually and press Enter to continue...")

🧠 Strategy 3: Use CAPTCHA Solving Services (Ethical Use Only)

Services like 2Captcha, Anti-Captcha, or DeathByCaptcha use human workers or OCR to solve CAPTCHA challenges.

Example: Using 2Captcha with Python

python

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import requests

api_key = "YOUR_2CAPTCHA_API_KEY"

# Step 1: Send the site key

captcha_request = requests.get(

    f"http://2captcha.com/in.php?key={api_key}&method=userrecaptcha&googlekey=SITE_KEY&pageurl=PAGE_URL"

)

captcha_id = captcha_request.text.split('|')[1]

# Step 2: Poll for the result

import time

result = None

while True:

    time.sleep(5)

    resp = requests.get(f"http://2captcha.com/res.php?key={api_key}&action=get&id={captcha_id}")

    if resp.text == 'CAPCHA_NOT_READY':

        continue

    else:

        result = resp.text.split('|')[1]

        break

# Step 3: Inject response token

driver.execute_script(f'document.getElementById("g-recaptcha-response").innerHTML="{result}";')

⚠️ Use only on authorized or test platforms. Never bypass CAPTCHA on real websites without permission.

📁 Part 2: Handling File Uploads in Selenium

✅ Method 1: Using send_keys() (Best for standard HTML file inputs)

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upload_input = driver.find_element(By.ID, "file-upload")

upload_input.send_keys("/path/to/your/file.png")

This works only if the upload element is <input type="file">.

🔄 Method 2: Handling Hidden File Inputs

If the file input is hidden, make it visible first:

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driver.execute_script("document.getElementById('file-upload').style.display = 'block';")

upload_input = driver.find_element(By.ID, "file-upload")

upload_input.send_keys("/path/to/your/file.png")

🖱️ Method 3: Using OS-level Tools for Custom Upload Dialogs

If the site uses a JavaScript file picker or non-input-based UI, use PyAutoGUI or AutoIt.

Example with PyAutoGUI:

python

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import pyautogui

import time

driver.find_element(By.ID, "custom-upload-button").click()

# Wait for OS dialog to open

time.sleep(2)

# Type file path and press Enter

pyautogui.write("/path/to/your/file.png")

pyautogui.press("enter")

PyAutoGUI simulates actual keyboard input, so it works with native OS dialogs.

🔄 Method 4: Remote File Uploads (API or S3 URLs)

If the site uses file uploads via URL (like presigned S3), upload the file directly via HTTP.

🧪 Best Practices

Topic Tips

CAPTCHA Avoid triggering, solve ethically, or use test environments

File Uploads Prefer send_keys() for simple inputs

Hidden Inputs Use JavaScript to unhide

Complex Uploads Use desktop automation (PyAutoGUI or AutoIt)

Reliability Add retries and waits to handle slow loads or modal dialogs

✅ Summary

Challenge Recommended Technique

CAPTCHA (reCAPTCHA) Use CAPTCHA-solving APIs or manual pauses

CAPTCHA (basic math/image) Use OCR libraries or automate solving logic

File upload (HTML input) send_keys()

File upload (hidden input) Reveal input via JavaScript, then send_keys()

File upload (custom UI) PyAutoGUI or OS-level tools

Learn Selenium Python Training in Hyderabad

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