https://lapi.transitchicago.com/api/1.0/ttarrivals.aspx?key=API_KEY&mapid=40380&outputType=JSON This is a CTA API documentation https://www.transitchicago.com/developers/ttdocs/> It works in browser but in python not working and returning 403. I tried with header and sessions but not working url = "https://lapi.transitchicago.com/api/1.0/ttarrivals.aspx" # Request parameters params = { 'key': api_key, 'mapid': station_id, 'max': max_results, 'outputType': output_type } # Headers to mimic a browser headers = { 'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.124 Safari/537.36', 'Accept': 'application/json', } try: # Make the API request response = requests.get(url, params=params, headers=headers) headers = { 'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.110 Safari/537.3', 'Accept-Language': 'en-US,en;q=0.9', 'Accept-Encoding': 'gzip, deflate, br', 'Accept': 'text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8', 'Connection': 'keep-alive', 'Upgrade-Insecure-Requests': '1' } session = requests.Session() session.headers.update(headers) response = session.get(url) Continue reading...