How to Fix Slow WiFi on iPhone — 9 Fixes That Work

iPhone WiFi issues often involve iOS settings rather than hardware. Test your iPhone WiFi speed at instantspeedtest.net/ in Safari to measure current performance, then work through these iOS-specific fixes.

iPhone WiFi Fixes — Step by Step

Fix 1 — Forget and rejoin. Settings → WiFi → tap “i” next to your network → Forget This Network → rejoin with password. Forces fresh connection negotiation.

Fix 2 — Disable Private Wi-Fi Address (if causing issues). Settings → WiFi → tap “i” → Private Wi-Fi Address — some routers handle rotating MAC addresses poorly; disabling this stabilizes connection on older routers.

Fix 3 — Disable WiFi Assist. Settings → Cellular → scroll down → WiFi Assist — turn OFF. WiFi Assist switches to cellular when WiFi is slow, which can cause unpredictable behavior on borderline WiFi connections.

Fix 4 — Change DNS. Settings → WiFi → tap “i” next to your network → Configure DNS → Manual → add 1.1.1.1 and 1.0.0.1. Faster DNS improves page load start times.

Fix 5 — Reset network settings. Settings → General → Transfer or Reset → Reset → Reset Network Settings. Clears all WiFi passwords and settings — you’ll need to re-enter passwords.

Fix 6 — Disable Low Data Mode. Settings → WiFi → tap “i” → Low Data Mode — turn OFF if enabled. Low Data Mode limits background data and reduces connection performance.

Fix 7 — Update iOS. Settings → General → Software Update. Apple regularly patches network performance issues in iOS updates.

Fix 8 — Limit background app refresh. Settings → General → Background App Refresh — turn off for apps that don’t need real-time background updates. Reduces background bandwidth consumption.

Fix 9 — Check for router-iPhone compatibility issue. Some older routers have specific incompatibility issues with newer iOS versions. Check your router manufacturer’s firmware update page for iOS compatibility fixes if all other steps fail.

Related Guides

• How to Fix Slow WiFi on Android
• How to Speed Up Internet on Phone
• 2.4 GHz vs 5 GHz WiFi
• Best DNS Servers for Speed
• Internet Slow Only on One Device
• How to Test Mobile Data Speed

Frequently Asked Questions

Why is my iPhone WiFi slow on iOS 17/18?

iOS updates occasionally introduce WiFi regressions. Apple typically addresses these with point updates (e.g., iOS 17.1). If slow WiFi appeared immediately after an iOS update, check if a newer iOS version is available and install it. The “Reset Network Settings” fix (Fix 5) resolves many iOS update-related network issues by starting fresh with default network configuration.

Why is Safari slow on iPhone WiFi?

Safari uses iCloud Private Relay (on iCloud+ plans) which routes traffic through Apple’s servers, adding latency. Settings → [your name] → iCloud → Private Relay — disable it temporarily to test if Private Relay is causing the slowdown. Also, Safari’s Intelligent Tracking Prevention processes some requests differently than Chrome, occasionally appearing slower for specific sites.