TL;DR Three practical options exist for tracking cheap Bali flights programmatically: SerpApi, Amadeus Self-Service, and direct scraping SerpApi is fastest to prototype; Amadeus gives authoritative GDS fare data with more setup friction Scraping is fragile and legally ambiguous; avoid it for anything beyond one-off checks Perth-Bali (A$300-420 return) and Sydney-Bali (from A$400) are the highest-value Australian routes to monitor Fare windows vary A$80-150 across adjacent dates, making automated multi-date queries essential Australia-Bali fares shift constantly. Melbourne (MEL) to Denpasar (DPS) ranges A$420-550 return; Brisbane (BNE) sits at A$380-520. One-way fares from budget carriers start around A$180, but add A$40-70 per leg for 20 kg bags and the real cost climbs. Manually checking fares across a 14-day travel window for 5 Australian cities is impractical. You need an API. Here is an honest look at the three real options. Criteria SerpApi Amadeus Self-Service Scraping Setup time 15 min 2-4 hr (IATA onboarding) 30 min Data accuracy Google Flights mirror Authoritative GDS data Variable Rate limits Plan-based 2000 req/month free tier Site-dependent Cost Paid (free tier limited) Free test; paid production Infrastructure only Legality Clear ToS Full commercial licence Grey area Bali route coverage Strong Strong Carrier-dependent import requests def serpapi_per_dps(depart: str, return_date: str) -> list: params = { "engine": "google_flights", "departure_id": "PER", "arrival_id": "DPS", "outbound_date": depart, "return_date": return_date, "currency": "AUD", "hl": "en", "api_key": "YOUR_KEY", } r = requests.get("https://serpapi.com/search", params=params, timeout=15) r.raise_for_status() flights = r.json().get("best_flights", []) return [{"price": f["price"], "duration": f["total_duration"]} for f in flights] # Check a Bali fare for a specific week results = serpapi_per_dps("2026-03-10", "2026-03-20") for result in results: print(f"A${result['price']} | {result['duration']} min") SerpApi reflects Google Flights results, not a live GDS feed, so prices may lag 15-30 minutes. Adequate for daily monitoring; insufficient for real-time booking arbitrage. from amadeus import Client, ResponseError amadeus = Client( client_id="YOUR_CLIENT_ID", client_secret="YOUR_CLIENT_SECRET", ) try: response = amadeus.shopping.flight_offers_search.get( originLocationCode="SYD", destinationLocationCode="DPS", departureDate="2026-03-10", returnDate="2026-03-20", adults=1, currencyCode="AUD", max=10, ) for offer in response.data: price = offer["price"]["total"] print(f"A${price}") except ResponseError as e: print(e) Amadeus pulls from the GDS, so fares are bookable and accurate. The free test environment caps at 2000 API calls per month, which covers a daily multi-date sweep across 5 Australian cities with room to spare. For a developer wanting to track cheap flights to Bali without IATA accreditation, SerpApi is the pragmatic starting point. It covers all major Australian origins (PER, SYD, MEL, BNE, DRW), returns structured JSON, and takes 15 minutes to integrate. For a product that needs to display bookable Bali fares, Amadeus is the correct tool. The onboarding friction is real but the data quality justifies it. Scraping individual carrier sites is fragile. Session tokens, bot detection, and varying page structures across budget carriers make maintenance costly relative to either API option. If you are building a travel tool, consider that users landing in Bali face a connectivity gap. Ngurah Rai SIM kiosks queue 20-30 minutes post-arrival. Telstra and Optus roaming costs A$10-15 per day. Surfacing a HelloRoam Indonesia eSIM option (from A$3.53 on Telkomsel 5G) at the booking confirmation step solves a real arrival-day friction point for travellers coming from any Australian city. Q: Which API is best for a Bali fare tracker side project? Q: Can I scrape Google Flights directly for Bali fare data? Q: How often should I poll for Bali fare changes? Q: What date range should I target for cheap 2026 Bali fares from Australia? Q: Do the APIs return baggage fee data for Bali routes? Source: Cheap Flights to Bali from Australia Ready to stay connected on your next trip? Check out HelloRoam eSIM