A JSON file of all possible Singapore postal codes and their respective latlongs based on the OneMap API by Singapore Land Authority here. Updated as at 22 June 2023.

I've also added the Elixir-based crawler if you're interested to see what's under the hood.

1. cd into onemap folder
2. run in terminal: mix deps.get
3. run in terminal: iex -S mix run -e "Crawly.Engine.start_spider(OneMapScraper)"

Note: This crawler only takes the latlong of the first address of the postal code. For example, postal 238823 has multiple latlongs, but the file only stores the first latlong.

onemap_crawler.ex: A file containing the main logic of the crawler.
SBData.ex: A file containing the list of existing postal codes as a result of the crawler back in 2020, courtesy of Scratchbac.
scrapeddata.ex: A file containing the list of postal codes as a result of the crawler in 2023.
onemap.ex: A module that checks scrapeddata.ex for any missing postal codes, by looking for missing values from 10000 to 999999. It also has code to check if there are postal codes returning empty values despite SBData having data on it (e.g. old postal codes). If there are, you can run Onemap.get_list_of_new_urls() and plug into the start_urls field of onemap_crawler.ex to double-check from OneMap's API.