as-metadata (formerly asn-info)

📢 Heads up: This repo has been upgraded! Now includes a new JSON format with full country names and origin tracking, plus country codes in CSV. The repo has been renamed to as-metadata to reflect the richer dataset. Check out MIGRATION.md for the quick migration steps (most users just need to update URLs).

A comprehensive dataset of autonomous system metadata for all assigned ASNs (autonomous system numbers). Includes handle, organization name, and country code sourced from regional internet registries (RIR). Updated daily when the underlying data changes.

Perfect for offline lookups, network analysis, threat intelligence, or any project where you need to map ASNs to organizations—no API rate limits, no external dependencies.

Available formats: JSON and CSV

JSON format:

[
  {
    "asn": 4711,
    "metadata": {
      "handle": "INTEC",
      "description": "INTEC Inc.",
      "countryCode": "JP",
      "country": "Japan",
      "origin": "authoritative"
    }
  },
  {
    "asn": 4712,
    "metadata": {
      "handle": "JT-NET",
      "description": "JAPAN TOBACCO INC.",
      "countryCode": "JP",
      "country": "Japan",
      "origin": "authoritative"
    }
  }
]

CSV format:

asn,handle,description,country-code
0,IANA-RSVD-0,Internet Assigned Numbers Authority,US
1,LVLT-1,Level 3 Parent LLC,US
2,UDEL-DCN,University of Delaware,US
3,MIT-GATEWAYS,Massachusetts Institute of Technology,US
4,ISI-AS,University of Southern California,US
5,SYMBOLICS,WFA Group LLC,US
6,BULL-HN,ATOS IT Solutions and Services Inc.,US
7,DSTL,The Defence Science and Technology Laboratory,GB
.
.
.

Field descriptions

Common fields (JSON and CSV)

• asn: Autonomous System Number
• handle: Registry handle/identifier
• description: Organization name or description
• country-code (CSV): ISO 3166-1 alpha-2 country code (XX if unknown)
• countryCode (JSON): ISO 3166-1 alpha-2 country code

JSON-only fields

• country: Full country name
• origin: Metadata source indicator
  • authoritative: From authoritative source
  • inferred: Inferred from routing information; may be inaccurate
  • overlaid: Metadata overlay from as-overlay applied
  • none: No metadata available

Update notes

• 2026-01-03: Repository renamed to as-metadata, CSV format changed to 4 columns (added country-code), JSON format added. See MIGRATION.md for details.
• 2025-08-03: Removed opinionated handle cleanup and removed quotes around descriptions to improve RFC4180 compliance
• 2023-09-03: Removed PEM certificates from description field

How to use

Download the data directly:

JSON:

curl -O https://raw.githubusercontent.com/ipverse/as-metadata/master/as.json

CSV:

curl -O https://raw.githubusercontent.com/ipverse/as-metadata/master/as.csv

Or just clone the repo if that's your thing.

Use cases

• Figure out who owns an ASN
• Enrich your IP intelligence tools
• Threat hunting and security research
• BGP analysis and network research
• Building dashboards or monitoring tools
• Offline lookups (no API rate limits to deal with)
• Pretty much anything where you need to map ASNs to operators

Related projects

• as-overlay: Autonomous system metadata overlays that supplement and enhance the authoritative data in this repository. When overlay data is applied, entries will have an origin value of overlaid in the JSON format.

Questions or issues?

Head over to the feedback repo if you have questions, issues, or suggestions.

License

This data is released under CC0 1.0 Universal.