The 1.3MB JSON file being discussed is literally sent gzipped. https://www.barclays.co.uk/content/dam/json-files/TelephoneNumberChecker_26_03_2021.json https:/

The 1.3MB JSON file being discussed is literally sent gzipped. https://www.barclays.co.uk/content/dam/json-files/TelephoneNumberChecker_26_03_2021.json https://www.barclays.co.uk/content/dam/json-files/TelephoneN... content-encoding: gzip content-length: 186136 Don't be misled by the fact that your browser transparently hides the compression from you.