diff --git a/apps/builder/src/components/UIBuilder/StepContractDefinition/StepContractDefinition.tsx b/apps/builder/src/components/UIBuilder/StepContractDefinition/StepContractDefinition.tsx
index c0157534..62ee9a54 100644
--- a/apps/builder/src/components/UIBuilder/StepContractDefinition/StepContractDefinition.tsx
+++ b/apps/builder/src/components/UIBuilder/StepContractDefinition/StepContractDefinition.tsx
@@ -4,6 +4,8 @@ import { useCallback, useMemo, useState } from 'react';
 
 import { NetworkServiceErrorBanner } from '@openzeppelin/ui-components';
 
+import { filterUnhealthyServicesForContractDefinitionStep } from './utils/filterUnhealthyServicesForContractDefinitionStep';
+
 import { ActionBar } from '../../Common/ActionBar';
 import { STEP_INDICES } from '../constants/stepIndices';
 import {
@@ -52,6 +54,7 @@ export function StepContractDefinition({
     definitionJson: contractDefinitionJson,
     error: contractDefinitionError,
     source: contractDefinitionSource,
+    metadata: contractDefinitionMetadata,
     requiresManualReload,
   } = contractState;
 
@@ -98,11 +101,30 @@ export function StepContractDefinition({
     });
 
   // Proactive network service health check
-  const { hasUnhealthyServices, unhealthyServices } = useNetworkServiceHealthCheck(
-    adapter,
-    networkConfig
+  const { unhealthyServices } = useNetworkServiceHealthCheck(adapter, networkConfig);
+
+  const unhealthyServicesForBanners = useMemo(
+    () =>
+      filterUnhealthyServicesForContractDefinitionStep(unhealthyServices, {
+        contractSource: contractDefinitionSource,
+        contractSchema,
+        contractMetadata: contractDefinitionMetadata,
+        contractDefinitionError,
+        isContractLoading: isLoading || isLoadingFromService,
+      }),
+    [
+      unhealthyServices,
+      contractDefinitionSource,
+      contractSchema,
+      contractDefinitionMetadata,
+      contractDefinitionError,
+      isLoading,
+      isLoadingFromService,
+    ]
   );
 
+  const hasUnhealthyServicesForBanners = unhealthyServicesForBanners.length > 0;
+
   // Form-store synchronization
   useFormSync({
     debouncedManualDefinition,
@@ -162,9 +184,9 @@ export function StepContractDefinition({
         isWidgetExpanded={isWidgetExpanded}
       />
 
-      {/* Show banners for unhealthy network services */}
-      {hasUnhealthyServices &&
-        unhealthyServices.map((service) => (
+      {/* Show banners for unhealthy network services (suppress explorer noise when load succeeds without it) */}
+      {hasUnhealthyServicesForBanners &&
+        unhealthyServicesForBanners.map((service) => (
           <NetworkServiceErrorBanner
             key={service.serviceId}
             networkConfig={networkConfig}
diff --git a/apps/builder/src/components/UIBuilder/StepContractDefinition/utils/__tests__/filterUnhealthyServicesForContractDefinitionStep.test.ts b/apps/builder/src/components/UIBuilder/StepContractDefinition/utils/__tests__/filterUnhealthyServicesForContractDefinitionStep.test.ts
new file mode 100644
index 00000000..f5345fa2
--- /dev/null
+++ b/apps/builder/src/components/UIBuilder/StepContractDefinition/utils/__tests__/filterUnhealthyServicesForContractDefinitionStep.test.ts
@@ -0,0 +1,111 @@
+import { describe, expect, it } from 'vitest';
+
+import type { ContractSchema } from '@openzeppelin/ui-types';
+
+import type { ServiceHealthStatus } from '../../hooks/useNetworkServiceHealthCheck';
+import {
+  filterUnhealthyServicesForContractDefinitionStep,
+  isSourcifyFetchedMetadata,
+} from '../filterUnhealthyServicesForContractDefinitionStep';
+
+const explorerUnhealthy: ServiceHealthStatus = {
+  serviceId: 'explorer',
+  serviceLabel: 'Block Explorer',
+  isHealthy: false,
+  error: 'API key is required',
+};
+
+const rpcUnhealthy: ServiceHealthStatus = {
+  serviceId: 'rpc',
+  serviceLabel: 'RPC',
+  isHealthy: false,
+  error: 'Connection refused',
+};
+
+const minimalSchema = { address: '0xabc' } as ContractSchema;
+
+describe('isSourcifyFetchedMetadata', () => {
+  it('returns true for sourcify URLs', () => {
+    expect(isSourcifyFetchedMetadata({ fetchedFrom: 'https://repo.sourcify.dev/...' })).toBe(true);
+    expect(isSourcifyFetchedMetadata({ fetchedFrom: 'Sourcify' })).toBe(true);
+  });
+
+  it('returns false for explorer or missing', () => {
+    expect(isSourcifyFetchedMetadata({ fetchedFrom: 'https://etherscan.io/address/0x' })).toBe(
+      false
+    );
+    expect(isSourcifyFetchedMetadata(null)).toBe(false);
+    expect(isSourcifyFetchedMetadata({})).toBe(false);
+  });
+});
+
+describe('filterUnhealthyServicesForContractDefinitionStep', () => {
+  it('keeps non-explorer unhealthy services', () => {
+    const out = filterUnhealthyServicesForContractDefinitionStep(
+      [rpcUnhealthy, explorerUnhealthy],
+      {
+        contractSource: null,
+        contractSchema: null,
+        contractMetadata: null,
+        contractDefinitionError: null,
+        isContractLoading: false,
+      }
+    );
+    expect(out).toEqual([rpcUnhealthy, explorerUnhealthy]);
+  });
+
+  it('hides explorer while contract is loading', () => {
+    const out = filterUnhealthyServicesForContractDefinitionStep([explorerUnhealthy], {
+      contractSource: null,
+      contractSchema: null,
+      contractMetadata: null,
+      contractDefinitionError: null,
+      isContractLoading: true,
+    });
+    expect(out).toEqual([]);
+  });
+
+  it('shows explorer when load failed', () => {
+    const out = filterUnhealthyServicesForContractDefinitionStep([explorerUnhealthy], {
+      contractSource: null,
+      contractSchema: null,
+      contractMetadata: null,
+      contractDefinitionError: 'Contract not verified',
+      isContractLoading: false,
+    });
+    expect(out).toEqual([explorerUnhealthy]);
+  });
+
+  it('hides explorer when manual ABI loaded successfully', () => {
+    const out = filterUnhealthyServicesForContractDefinitionStep([explorerUnhealthy], {
+      contractSource: 'manual',
+      contractSchema: minimalSchema,
+      contractMetadata: { verificationStatus: 'unknown' },
+      contractDefinitionError: null,
+      isContractLoading: false,
+    });
+    expect(out).toEqual([]);
+  });
+
+  it('hides explorer when fetch succeeded via Sourcify metadata', () => {
+    const out = filterUnhealthyServicesForContractDefinitionStep([explorerUnhealthy], {
+      contractSource: 'fetched',
+      contractSchema: minimalSchema,
+      contractMetadata: { fetchedFrom: 'https://repo.sourcify.dev/foo' },
+      contractDefinitionError: null,
+      isContractLoading: false,
+    });
+    expect(out).toEqual([]);
+  });
+
+  it('shows explorer when fetch succeeded from etherscan URL', () => {
+    const out = filterUnhealthyServicesForContractDefinitionStep([explorerUnhealthy], {
+      contractSource: 'fetched',
+      contractSchema: minimalSchema,
+      contractMetadata: { fetchedFrom: 'https://etherscan.io/address/0x' },
+      contractDefinitionError: null,
+      isContractLoading: false,
+    });
+    expect(out).toEqual([explorerUnhealthy]);
+  });
+});
diff --git a/apps/builder/src/components/UIBuilder/StepContractDefinition/utils/filterUnhealthyServicesForContractDefinitionStep.ts b/apps/builder/src/components/UIBuilder/StepContractDefinition/utils/filterUnhealthyServicesForContractDefinitionStep.ts
new file mode 100644
index 00000000..9c2f1799
--- /dev/null
+++ b/apps/builder/src/components/UIBuilder/StepContractDefinition/utils/filterUnhealthyServicesForContractDefinitionStep.ts
@@ -0,0 +1,64 @@
+import type { ContractDefinitionMetadata, ContractSchema } from '@openzeppelin/ui-types';
+
+import type { ServiceHealthStatus } from '../hooks/useNetworkServiceHealthCheck';
+
+/**
+ * True when contract metadata indicates the ABI was satisfied via Sourcify
+ * (used to suppress explorer probe errors after a successful fallback).
+ */
+export function isSourcifyFetchedMetadata(
+  metadata: ContractDefinitionMetadata | null | undefined
+): boolean {
+  const from = metadata?.fetchedFrom?.toLowerCase() ?? '';
+  return from.includes('sourcify');
+}
+
+export interface ContractDefinitionBannerContext {
+  contractSource: 'fetched' | 'manual' | null;
+  contractSchema: ContractSchema | null;
+  contractMetadata: ContractDefinitionMetadata | null;
+  contractDefinitionError: string | null;
+  isContractLoading: boolean;
+}
+
+/**
+ * Filters proactive {@link ServiceHealthStatus} rows before showing {@link NetworkServiceErrorBanner}.
+ *
+ * For the block explorer service, hides the banner while a contract load is in flight (avoids
+ * flashing "explorer unavailable" before Sourcify is tried), when the user supplied a manual ABI,
+ * or when an automatic fetch succeeded via Sourcify after the explorer probe failed.
+ *
+ * Other unhealthy services (e.g. RPC) are always kept.
+ */
+export function filterUnhealthyServicesForContractDefinitionStep(
+  unhealthyServices: ServiceHealthStatus[],
+  ctx: ContractDefinitionBannerContext
+): ServiceHealthStatus[] {
+  return unhealthyServices.filter((service) => {
+    if (service.serviceId !== 'explorer') {
+      return true;
+    }
+
+    if (ctx.isContractLoading) {
+      return false;
+    }
+
+    if (ctx.contractDefinitionError) {
+      return true;
+    }
+
+    if (!ctx.contractSchema) {
+      return true;
+    }
+
+    if (ctx.contractSource === 'manual') {
+      return false;
+    }
+
+    if (ctx.contractSource === 'fetched' && isSourcifyFetchedMetadata(ctx.contractMetadata)) {
+      return false;
+    }
+
+    return true;
+  });
+}