How to Fix Slow WiFi on iPhone

Published March 7, 2026 · 7 min read

Your iPhone says it's connected to WiFi, but everything loads at a crawl. Pages time out, videos buffer endlessly, and video calls keep freezing. Before you blame your ISP, there are several things you can diagnose and fix yourself. Here's a systematic approach to finding and solving the problem.

Step 1: Confirm It's Actually Slow

Before troubleshooting, establish a baseline. Run a speed test to see what you're actually getting versus what your ISP plan promises. Open PingKit, tap Speed Test, and note your download speed, upload speed, and latency.

• If you're getting close to your plan speed, the issue might be with a specific app or service, not your WiFi
• If speeds are significantly below your plan (say, 20 Mbps on a 200 Mbps plan), keep reading
• If speeds are fine on WiFi but slow on one device, the problem is device-specific

Step 2: Check Your Signal Strength

WiFi performance drops dramatically with distance and obstacles. A single wall can cut your speed in half. Two or three walls and you might be getting a fraction of your router's capability.

Check your connection details in PingKit's Network Info tool. Look for your signal strength — anything below -70 dBm means you're too far from the router or there's too much interference.

How to improve signal strength:

• Move your router to a central location — corners and closets are the worst spots
• Elevate the router — placing it on a shelf or mounting it on a wall improves coverage
• Remove obstacles — fish tanks, mirrors, and concrete walls are particularly bad for WiFi
• Consider a mesh system — if your home is large or has thick walls, a single router won't cut it

Step 3: Switch WiFi Bands

Modern routers broadcast on two frequencies:

• 2.4 GHz — Longer range but slower (max ~150 Mbps real-world). More prone to interference from microwaves, Bluetooth, and neighbours' networks
• 5 GHz — Shorter range but much faster (up to 800+ Mbps). Less interference because there are more channels available

If your router has separate network names for each band (e.g., "MyNetwork" and "MyNetwork_5G"), try connecting to the 5 GHz network when you're close to the router. Switch to 2.4 GHz only when you're far away and need range over speed.

Step 4: Check for Network Congestion

Too many devices competing for bandwidth is one of the most common causes of slow WiFi. Use PingKit's LAN Discovery tool to see every device connected to your network. You might be surprised how many there are — smart TVs, game consoles, security cameras, smart speakers, and phones all add up.

• Identify bandwidth hogs — streaming a 4K video uses about 25 Mbps per stream
• Check for unknown devices — if you see devices you don't recognise, someone might be on your network uninvited
• Stagger heavy usage — avoid running backups while streaming or during video calls

Step 5: Restart Your Router

It sounds simple, but restarting your router fixes more problems than you'd expect. Routers accumulate stale connection tables, memory leaks, and cached routing data over time. A restart clears all of this.

1. Unplug your router from power
2. Wait 30 seconds (this fully clears the memory)
3. Plug it back in and wait 2-3 minutes for it to fully boot
4. Run another speed test to compare

Step 6: Check for Interference

WiFi channels are like lanes on a motorway. If your router and your neighbour's router are on the same channel, they interfere with each other and both slow down.

Most routers auto-select channels, but they don't always pick the best one. Log into your router's admin panel and try manually setting the channel:

• For 2.4 GHz: Use channels 1, 6, or 11 (the only non-overlapping channels)
• For 5 GHz: There are many more channels available, so interference is less common. Try channels in the DFS range (52-144) if your router supports them

Step 7: Reset iPhone Network Settings

If other devices on your WiFi work fine but your iPhone is slow, the problem might be on the phone itself. Corrupted network settings can cause persistent slowness.

1. Go to Settings > General > Transfer or Reset iPhone
2. Tap Reset > Reset Network Settings
3. Enter your passcode and confirm

This resets all WiFi passwords, VPN settings, and cellular preferences. You'll need to reconnect to your WiFi network, but it often resolves stubborn connection issues.

Step 8: Check Your DNS

Slow DNS resolution makes every website feel sluggish, even if your raw speed is fine. Your router usually uses your ISP's DNS servers by default, and these aren't always the fastest.

Try switching to a faster DNS provider. You can use PingKit's Ping tool to test latency to different DNS servers and see which responds fastest from your location:

• Cloudflare: 1.1.1.1 and 1.0.0.1
• Google: 8.8.8.8 and 8.8.4.4
• Quad9: 9.9.9.9 (also blocks malware domains)

Change DNS on your iPhone in Settings > WiFi > tap your network > Configure DNS > Manual. For a network-wide fix, change it on your router instead.

When to Call Your ISP

If you've tried everything above and speeds are still well below what you're paying for, it's time to contact your ISP. Before you call, gather evidence:

• Run speed tests at different times of day and save the results
• Run PingKit's MTR to your ISP's gateway to check for packet loss on their network
• Note the specific speeds you're getting versus what your plan promises

Having this data turns a vague "my internet is slow" complaint into a specific, evidence-backed support request that's much more likely to get results.