---
category: Reference
title: Location Reference
description: Complete technical specification for Location monitoring
---

openstatus monitors your endpoints from multiple global locations to ensure accurate uptime and latency reporting. Locations span several infrastructure providers (Fly.io, Railway, and Koyeb), so IP availability varies: Fly.io regions expose both IPv4 and IPv6 addresses, Railway regions are IPv4-only, and Koyeb does not provide static IPs.

You can use these locations to:

- Configure region-specific checks.
- Allowlist monitoring IPs in your firewall.
- Understand where requests originate during synthetic monitoring.

## Three forms of the same region code

The same probe is addressed by a different spelling depending on the surface you are using:

| Surface | Form | Example |
|---|---|---|
| Dashboard, CLI, deprecated v1 REST API | **bare** code | `iad`, `fra`, `koyeb_fra`, `railway_us-east4-eqdc4a` |
| Terraform provider | **prefixed, hyphenated** | `fly-iad`, `fly-fra`, `koyeb-fra`, `railway-us-east4` |
| ConnectRPC API and the SDKs | the **protobuf enum** value | `REGION_FLY_IAD`, `REGION_FLY_FRA`, `REGION_KOYEB_FRA`, `REGION_RAILWAY_US_EAST4` |

The SDKs expose the enum as a generated constant rather than a raw string — `Region.FLY_IAD` in
the Node.js SDK, `Region::REGION_FLY_IAD` in PHP — so you rarely type the value out.

Pick whichever form the surface you are using expects. The tables below list the bare and
prefixed codes; the enum value is the prefixed code upper-cased with `-` replaced by `_` and
`REGION_` prepended.

### Fly.io regions and monitoring IPs

Below is the complete list of regions used for monitoring, along with their associated IPv4 and IPv6 addresses.

| Region code | Prefixed code | Location name      | IPv4 address      | IPv6 address                   |
|-------------|---------------|-------------------|-------------------|-------------------------------|
| ams         | `fly-ams` | Amsterdam         | 209.71.64.1       | 2a09:8280:e601:1:0:22:b79b:0  |
| arn         | `fly-arn` | Stockholm         | 209.71.98.189     | 2a09:8280:e602:1:0:22:b79b:0  |
| bom         | `fly-bom` | Mumbai            | 209.71.68.172     | 2a09:8280:e605:1:0:22:b79b:0  |
| cdg         | `fly-cdg` | Paris             | 209.71.86.183     | 2a09:8280:e607:1:0:22:b79b:0  |
| dfw         | `fly-dfw` | Dallas            | 209.71.71.89      | 2a09:8280:e609:1:0:22:b79b:0  |
| ewr         | `fly-ewr` | Secaucus, New Jersey | 209.71.69.221     | 2a09:8280:e610:1:0:22:b79b:0  |
| fra         | `fly-fra` | Frankfurt         | 209.71.90.204     | 2a09:8280:e612:1:0:22:b79b:0  |
| gru         | `fly-gru` | São Paulo         | 209.71.94.28      | 2a09:8280:e615:1:0:22:b79b:0  |
| iad         | `fly-iad` | Ashburn, Virginia | 209.71.81.6       | 2a09:8280:e618:1:0:22:b79b:0  |
| jnb         | `fly-jnb` | Johannesburg      | 209.71.83.120     | 2a09:8280:e620:1:0:22:b79b:0  |
| lax         | `fly-lax` | Los Angeles       | 209.71.91.96      | 2a09:8280:e621:1:0:22:b79b:0  |
| lhr         | `fly-lhr` | London            | 209.71.85.82      | 2a09:8280:e622:1:0:22:b79b:0  |
| nrt         | `fly-nrt` | Tokyo             | 209.71.88.150     | 2a09:8280:e625:1:0:22:b79b:0  |
| ord         | `fly-ord` | Chicago           | 209.71.89.1       | 2a09:8280:e626:1:0:22:b79b:0  |
| sin         | `fly-sin` | Singapore         | 209.71.80.112     | 2a09:8280:e632:1:0:22:b79b:0  |
| sjc         | `fly-sjc` | San Jose          | 209.71.101.37     | 2a09:8280:e633:1:0:22:b79b:0  |
| syd         | `fly-syd` | Sydney            | 209.71.97.108     | 2a09:8280:e634:1:0:22:b79b:0  |
| yyz         | `fly-yyz` | Toronto           | 209.71.99.51      | 2a09:8280:e637:1:0:22:b79b:0  |


## Railway regions and monitoring IPs

Below is the complete list of Railway regions used for monitoring, along with their associated IPv4 addresses.

| Region code                    | Prefixed code               | Location name     | IPv4 address      |
|--------------------------------|-----------------------------|------------------|-------------------|
| railway_europe-west4-drams3a   | `railway-europe-west4`      | Europe West      | 208.77.244.15     |
| railway_asia-southeast1-eqsg3a | `railway-asia-southeast1`   | Asia Southeast   | 208.77.246.15     |
| railway_us-east4-eqdc4a        | `railway-us-east4`          | US East          | 162.220.234.15    |
| railway_us-west2               | `railway-us-west2`          | US West          | 162.220.232.99    |

## Koyeb regions

Koyeb does not provide static IP addresses for their regions, so IPs are not available for allowlisting. For details, see Koyeb's [documentation](https://www.koyeb.com/docs/faqs/general#i-want-to-restrict-access-to-a-database-or-other-application-by-ip-address-what-ip-addresses-does-koyeb-use).

| Region code  | Prefixed code | Location name           |
|--------------|---------------|-------------------------|
| koyeb_fra    | `koyeb-fra`   | Frankfurt, Germany      |
| koyeb_par    | `koyeb-par`   | Paris, France           |
| koyeb_sfo    | `koyeb-sfo`   | San Francisco, USA      |
| koyeb_sin    | `koyeb-sin`   | Singapore               |
| koyeb_tyo    | `koyeb-tyo`   | Tokyo, Japan            |
| koyeb_was    | `koyeb-was`   | Washington, USA         |

---

**Note:**  

- Where available, IPv4 and IPv6 addresses are provided for allowlisting and diagnostics (Fly.io regions only; Railway is IPv4-only and Koyeb has no static IPs).
- Location names are for reference and may be used in the dashboard UI.