Why are my eSIM speeds slow and how can I fix it?

Slow eSIM speeds during travel usually come from one of five causes: weak signal at your specific location, a congested cell tower (lots of people in one spot), throttling because your plan hit its data cap, your phone connected to 3G or 4G instead of 5G where 5G is available, or background apps eating up bandwidth. Run a speed test first (Speedtest.net app or fast.com) to confirm the actual speed, then work through the causes in order. Most slow-speed issues resolve in under 10 minutes.

Below: how to diagnose the real cause, the specific fix for each, and what slow speeds you should reasonably expect on a travel eSIM.

First, measure the actual speed

Before assuming "slow," get a number. Run a speed test:

• Speedtest by Ookla: most reliable. Free app on iOS and Android, or speedtest.net in a browser.
• fast.com: Netflix's own speed test, browser-based, focuses on download.
• nperf.com: alternative with more details.

Run the test on cellular (Wi-Fi off). Note the download speed (Mbps), upload speed, and ping.

Typical speeds you should expect:

• 5G urban areas: 100-500 Mbps download.
• 4G LTE urban: 30-100 Mbps download.
• 4G LTE rural or congested: 10-30 Mbps.
• 3G fallback: 1-5 Mbps. (Should be rare in 2026.)

If your speed test shows numbers in those ranges, your speeds are normal for the network type. If you're getting 1-2 Mbps when you should be getting 50, something is wrong.

Cause 1: Weak signal

Look at the signal bars in your status bar. 1-2 bars (or weak signal indicator) means the radio path to the tower is poor. Even on 5G or fast 4G, weak signal caps the throughput severely.

Fixes:

• Move closer to a window if indoors.
• Step outside if possible; buildings, especially modern glass-and-concrete ones, block cellular signals.
• Move to a higher elevation if you're in a valley or basement.
• Try a different room or different side of the building.

If signal goes from 2 bars to 4 bars, speeds usually triple or more. Location matters enormously.

Cause 2: Congested cell tower

A cell tower has a fixed amount of capacity, shared among everyone connected to it. In high-density areas (festivals, sports events, transit hubs at rush hour, major tourist sites), the tower gets saturated and speeds drop for everyone.

Signs of congestion:

• Speed is fine at 6am or 11pm but slow at noon and 6pm.
• Speed is fine in your hotel but terrible at a popular restaurant nearby.
• You see full bars but speeds are 2-5 Mbps.

Fixes:

• Wait 30-60 minutes for the rush to clear.
• Move to a less crowded location.
• Use the local Wi-Fi as a backup if available.

Congestion is the network's problem, not yours. No phone fix exists.

Cause 3: Plan throttling after cap reached

Some Eflexsim plans throttle to slow speeds (often 128 Kbps to 1 Mbps) after you hit the data cap, rather than cutting off completely. Throttled speeds feel unusable: maps load, but slowly; video streaming is impossible; social media browses sluggishly.

Check:

1. Sign in to your Eflexsim account at eflexsim.com.
2. Go to Account → Orders → active eSIM.
3. Check remaining data balance.
4. If "0 GB remaining" or close to it, you've hit the cap.

Fix:

Top up the plan to add more data. The throttle lifts within minutes of the top-up applying. See how to top up an existing eSIM.

For unlimited plans, the situation is different: many "unlimited" plans have a high-speed tier that throttles to slower speeds after a soft cap. If you've used 30+ GB in a few days, you may have hit this. See do you offer unlimited data eSIM plans.

Cause 4: Connected to 3G/4G instead of 5G

Even if 5G is available at your location, your phone may be connected to 4G or 3G for one of these reasons:

• Your phone doesn't support 5G (iPhone 11 or older, older Galaxies and Pixels).
• 5G is disabled in your phone's cellular settings.
• The partner network in your country doesn't have 5G enabled for travel eSIMs (sometimes a roaming limitation).
• You're in a 5G dead spot within an otherwise 5G area.

Check your status bar: if it says LTE, 4G, or 3G, you're not on 5G. If it says 5G, 5G+, 5G UC, or 5G UW, you are.

Fixes:

• Enable 5G in cellular settings. See will I get 5G with an Eflexsim plan for the per-phone setup.
• Move to a different location to find a 5G tower.
• Accept that your trip's 4G speeds may be the best available.

Note: 4G LTE is fast enough for most travel use. The difference between 30 Mbps 4G and 200 Mbps 5G is unnoticeable for everyday web browsing, messaging, and social media. 5G matters most for heavy uploads, HD video calls, and 4K streaming.

Cause 5: Background apps eating bandwidth

If you have apps doing heavy background work (iCloud photo backup, OneDrive sync, OS updates downloading, podcast pre-fetching), your active-use apps share the remaining bandwidth and feel slow.

Check:

• iPhone: Settings → Cellular → scroll to see per-app data usage during the current period.
• Android: Settings → Network → Data usage → see top apps.

Apps with high background usage on your trip are usually iCloud Photos, Dropbox, Google Drive, OneDrive, and OS update mechanisms.

Fixes:

• Disable cellular for cloud sync apps. Settings → Cellular → toggle off for Photos, Dropbox, etc.
• Disable background app refresh for non-essential apps.
• Don't run OS updates on cellular; wait for Wi-Fi.

For data-usage management, see how much data do I actually need for my trip.

Other causes worth checking

A few less-common causes:

VPN slowdown. Running a VPN adds 10-30% overhead to data transfers. If using one for streaming home content, that's normal slowdown. Disable for speed tests to see your raw speed.

Phone in low-power mode. Some Android phones throttle cellular when battery is low or in battery-saver mode. Disable battery saver and re-test.

Time of day / partner network maintenance. Speeds sometimes drop during overnight maintenance windows. If you only see slowness at 2am-5am local time, that's likely it.

Hardware issue. Rare, but possible. If a friend's phone in the same location gets fast speeds and yours is slow consistently, your phone may have an antenna issue.

For data cap issues, see how to top up an existing eSIM. For 5G specifics, see will I get 5G with an Eflexsim plan. For no-connection issues, see data is on but apps won't connect.