diff --git a/backend/.env.example b/backend/.env.example
index dff41cff..8fc31e09 100644
--- a/backend/.env.example
+++ b/backend/.env.example
@@ -27,3 +27,7 @@ BLOCKCHAIN_API_SECRET="ef0b48e41f78d3ae85b1379b386f1bca"
 
 # run `flask gen-admin-auth` to create new password for admin
 ADMIN_PASS_HASH=18f97883b93a975deb9e29257a341a447302040da59cdc2d10ff65a5e57cc197
+
+# Blockchain explorer to link to. Top for mainnet, bottom for testnet.
+# EXPLORER_URL="https://explorer.zcha.in/"
+EXPLORER_URL="https://testnet.zcha.in/"
diff --git a/backend/grant/proposal/views.py b/backend/grant/proposal/views.py
index bc70f3f2..0cdeeed1 100644
--- a/backend/grant/proposal/views.py
+++ b/backend/grant/proposal/views.py
@@ -9,6 +9,7 @@ from grant.utils.auth import requires_auth, requires_team_member_auth, get_authe
 from grant.utils.exceptions import ValidationException
 from grant.utils.misc import is_email, make_url, from_zat, make_preview
 from sqlalchemy import or_
+from grant.settings import EXPLORER_URL
 
 from .models import (
     Proposal,
@@ -454,7 +455,7 @@ def post_contribution_confirmation(contribution_id, to, amount, txid):
     send_email(contribution.user.email_address, 'contribution_confirmed', {
         'contribution': contribution,
         'proposal': contribution.proposal,
-        'tx_explorer_url': f'https://explorer.zcha.in/transactions/{txid}',
+        'tx_explorer_url': f'{EXPLORER_URL}transactions/{txid}',
     })
 
     # Send to the full proposal gang
diff --git a/backend/grant/settings.py b/backend/grant/settings.py
index 0447646a..b515b703 100644
--- a/backend/grant/settings.py
+++ b/backend/grant/settings.py
@@ -52,6 +52,8 @@ BLOCKCHAIN_API_SECRET = env.str("BLOCKCHAIN_API_SECRET")
 
 ADMIN_PASS_HASH = env.str("ADMIN_PASS_HASH")
 
+EXPLORER_URL = env.str("EXPLORER_URL", default="https://explorer.zcha.in/")
+
 UI = {
   'NAME': 'ZF Grants',
   'PRIMARY': '#CF8A00',
diff --git a/frontend/.env.example b/frontend/.env.example
index 4ac16085..eb4528ba 100644
--- a/frontend/.env.example
+++ b/frontend/.env.example
@@ -11,3 +11,7 @@ BACKEND_URL=http://localhost:5000
 # sentry 
 # SENTRY_DSN=https://PUBLICKEY@sentry.io/PROJECTID
 # SENTRY_RELEASE="optional, provides sentry logging with release info"
+
+# Blockchain explorer to link to. Top for mainnet, bottom for testnet.
+# EXPLORER_URL="https://explorer.zcha.in/"
+EXPLORER_URL="https://testnet.zcha.in/"
diff --git a/frontend/client/utils/formatters.ts b/frontend/client/utils/formatters.ts
index b0d61ca4..e45ff6d0 100644
--- a/frontend/client/utils/formatters.ts
+++ b/frontend/client/utils/formatters.ts
@@ -87,5 +87,5 @@ export function formatZcashCLI(address: string, amount?: string | number, memo?:
 }
 
 export function formatTxExplorerUrl(txid: string) {
-  return `https://explorer.zcha.in/transactions/${txid}`;
+  return `${process.env.EXPLORER_URL}transactions/${txid}`;
 }
diff --git a/frontend/config/env.js b/frontend/config/env.js
index 7e339d08..e9f1adce 100644
--- a/frontend/config/env.js
+++ b/frontend/config/env.js
@@ -41,14 +41,6 @@ envProductionRequiredHandler(
   'http://localhost:' + (process.env.PORT || 3000),
 );
 
-if (!process.env.SENTRY_RELEASE) {
-  process.env.SENTRY_RELEASE = undefined;
-}
-
-if (!process.env.BACKEND_URL) {
-  process.env.BACKEND_URL = 'http://localhost:5000';
-}
-
 const appDirectory = fs.realpathSync(process.cwd());
 process.env.NODE_PATH = (process.env.NODE_PATH || '')
   .split(path.delimiter)
@@ -58,12 +50,13 @@ process.env.NODE_PATH = (process.env.NODE_PATH || '')
 
 module.exports = () => {
   const raw = {
-    BACKEND_URL: process.env.BACKEND_URL,
+    BACKEND_URL: process.env.BACKEND_URL || 'http://localhost:5000',
+    EXPLORER_URL: process.env.EXPLORER_URL || 'https://chain.so/zcash/',
     NODE_ENV: process.env.NODE_ENV || 'development',
     PORT: process.env.PORT || 3000,
     PUBLIC_HOST_URL: process.env.PUBLIC_HOST_URL,
     SENTRY_DSN: process.env.SENTRY_DSN || null,
-    SENTRY_RELEASE: process.env.SENTRY_RELEASE,
+    SENTRY_RELEASE: process.env.SENTRY_RELEASE || undefined,
   };
 
   // Stringify all values so we can feed into Webpack DefinePlugin