Complete Guide to Choosing an Overseas SIM Card: Testing the Performance of 10 Services

Essential communication environment for overseas travel and business trips. With overseas SIM cards and eSIMs, you can achieve both high-speed communication and low costs on-site, attracting the attention of many travelers. However, there are many people who have questions such as “Which plan suits me best?” and “What is the difference from roaming?”

In this article, we thoroughly evaluate 10 popular overseas SIM card and eSIM providers based on three axes: price, communication speed, and speed restrictions. Based on actual user experiences with each service, we will introduce how to find the perfect plan for you.

Thorough Comparison of 10 Overseas SIM Card and eSIM Services

To select the optimal overseas SIM card, we conducted evaluations based on the following three points:

Evaluation Item ①: Cost Reduction Effect
Evaluation Item ②: Actual Communication Quality
Evaluation Item ③: Likelihood of Capacity Restrictions

Performance Rankings

【TOP】World eSIM (Vision): Overall Score 4.68

Excellent communication quality in Korea and Hawaii. Outstanding cost performance as well

World eSIM, supporting over 200 countries, is a data-only overseas SIM service provided by Vision. It can be purchased instantly via app or web, and fully supports tethering functions. The 10% discount when purchasing through the app is also a major benefit for users.

Advantages:

• Smooth video streaming in Korea and Hawaii
• No restrictions even after using 15GB in Korea
• Cheapest in Thailand, competitive in other regions

Points to consider:

• Slightly higher prices in Taiwan

Glocal eSIM (GlocalNet): Overall Score 4.36

Ideal balance of cost control and communication quality

You can start using immediately by scanning a QR code, with flexible plans from 3 to 30 days. Supports 5G and Japanese language support, making it a reliable overseas SIM service from GlocalNet.

Advantages:

• Ensures sufficient speed for video viewing in Korea
• No restrictions after using 15GB in Korea
• Cheapest in Thailand, with competitive pricing elsewhere

Points to consider:

• Speed fluctuations observed depending on the time in Hawaii
• Prices tend to be higher in Italy

Ubigi (Transatel): Overall Score 4.21

Strong high-speed communication in Hawaii. Price varies by region

A global eSIM provided by Transatel, usable in over 200 countries. Offers 7-30 day plans, as well as monthly and yearly plans, with easy management of remaining data and additional purchases via app.

Advantages:

• Good streaming experience in Hawaii
• Lower risk of speed restrictions with 1-day use in Korea
• Excellent balance of price and performance in Hawaii and Italy

Points to consider:

• Speed may be insufficient for SNS browsing in Korea
• No 3-day plan (challenging for short trips)
• Takes time to confirm activation completion

eSIM square (Telecom Square): Overall Score 4.17

Fast communication shines, but price range is on the higher side

Handles SIMs for over 200 countries and regions, with recharge options available as needed. Provides peace of mind with 24-hour Japanese chat support.

Advantages:

• Sufficient speed for video viewing in Korea and Hawaii
• No restrictions after using 15GB in Korea
• Competitive pricing for Korea plans

Points to consider:

• Higher prices in Hawaii and Italy
• No 3-day plans for Taiwan and Thailand

AIRALO: Overall Score 4.08

Cheapest with discounts. Speed remains at a standard level

An overseas SIM provided by AIRALO from Singapore. Supports 53 languages, multiple currency payments, and 24-hour support.

Advantages:

• 15% discount with referral code
• Cheapest in Korea, Hawaii, Italy; affordable in Taiwan
• Less likely to face restrictions browsing text sites in Korea

Points to consider:

• No 3-day plan for Thailand
• Insufficient speed for video streaming

DHA SIM: Overall Score 4.02

Limited supported countries but high cost performance where available

Supports both eSIM and physical cards flexibly. eSIM uses QR code delivery, but note that delivery is required to receive the code.

Advantages:

• Sufficient speed for video viewing in Korea and Hawaii
• Cheapest in Taiwan, affordable in Korea and Hawaii

Points to consider:

• No 3-day plan for Thailand, 7-day plan for Italy
• Possible speed restrictions during long-term use in Korea

TRAVeSIM (a2network): Overall Score 3.99

Pricing advantage but some issues with communication speed

Covers over 140 countries, with multi-country travel plans available. Supports 5G and provides Japanese support 24/7.

Advantages:

• Difficult to face restrictions even with all-day video streaming in Korea
• Cost competitiveness in Korea, Taiwan, Hawaii, Italy

Points to consider:

• Insufficient speed for video viewing
• No 3-day plan for Thailand

Holafly: Overall Score 3.82

Affordable prices are attractive, but basic speeds are low

A Spain-origin provider offering unlimited plans in over 120 countries, with monthly and yearly options. Purchases and referrals earn HolaCoins that can be used for discounts.

Advantages:

• Competitive pricing across multiple regions
• Less restrictions when viewing videos in Korea

Points to consider:

• Low basic speeds, limited SNS browsing

Trifa: Overall Score 3.72

Fewer restrictions but issues with speed and cost

Supports over 200 countries and regions, with easy purchase and activation via app. Features 24-hour Japanese chat and a variety of plans.

Advantages:

• Good video streaming in Hawaii
• No restrictions after using 15GB in Korea

Points to consider:

• Insufficient basic speed in Korea
• Overall higher prices, not recommended for budget-conscious users

SkyeSiM (FREEDiVE): Overall Score 3.71

High prices outside Hawaii. Speed stability is also uncertain

A renewed service from FREEDiVE. Allows selection of data volume and duration on a daily basis, supporting over 120 countries. Easy purchase via web, with multiple payment options.

Advantages:

• Relatively affordable in Hawaii

Points to consider:

• Higher prices in Korea, Taiwan, Thailand, Italy
• No unlimited plan for Italy
• Significant speed fluctuations depending on time

Points for Choosing an Overseas SIM Card

To select the best overseas SIM for your needs, it is crucial to organize your travel destinations and usage patterns in advance. Prioritize based on your main activities—if you watch a lot of videos, focus on speed; for short business trips, cost may be more important. Clarifying your priorities makes it easier to find the most suitable service.

Supervised by: Atsushi Ishikawa (Telecommunications Technology Journalist)
Guide: Kenji Takayama (Telecommunications Sales Advisor)