You’re planning a month across Southeast Asia—Bangkok, Singapore, Bali, Ho Chi Minh City. Your carrier wants $10-15 per day for roaming. That’s $300-450 for the trip. You could buy physical SIM cards in each country, but that means finding stores in four different countries, dealing with four different languages, and swapping tiny cards every time you cross a border.
There’s a better way: One eSIM that works across multiple Asian countries. Or individual country eSIMs you install before leaving home and activate as you travel. No stores. No card swapping. No language barriers.
RedEx eSIM offers coverage across Asia with plans starting at $10.99 for 6GB over 7 days in Thailand, Japan, Singapore, and other popular destinations. Install before departure, activate when you land, and you’re connected in under 60 seconds.
This guide covers everything you need to know about using eSIM for Asia travel: which countries have the best coverage, how pricing compares between Southeast and Northeast Asia, and how to stay connected from Tokyo to Bali without overpaying.
Understanding Asia’s Mobile Landscape
Two Very Different Markets
Asian eSIM pricing and coverage split into two distinct regions:
| Region | Key Characteristics |
|---|---|
| Southeast Asia (Thailand, Vietnam, Malaysia, Indonesia, Philippines) | Highly competitive mobile markets; Very affordable pricing; Excellent urban coverage, variable rural coverage; Strong 4G LTE, growing 5G. |
| Northeast Asia (Japan, South Korea, Taiwan, Hong Kong) | Premium mobile markets; Higher pricing but excellent quality; Outstanding coverage including rural areas; Advanced 5G networks. |
| China | Separate category due to unique regulations and internet restrictions (Great Firewall). Most international eSIM providers don’t cover China or offer limited access. |
Network Quality Expectations
| Area Type | Coverage & Speed Details |
|---|---|
| Major Cities (Bangkok, Tokyo, Singapore, Seoul, Taipei) | Excellent 4G LTE and 5G coverage; Speeds: 30-100+ Mbps typical; No coverage concerns. |
| Tourist Areas (Phuket, Bali, Kyoto, Jeju Island) | Good to excellent coverage; 4G LTE standard; Speeds: 20-60 Mbps. |
| Rural Areas | Variable coverage depending on country. Japan and South Korea are excellent; Southeast Asia is good along main roads but limited in remote areas. |
| Islands & Remote Regions | Thai islands have good coverage in tourist areas; Indonesia is variable (best in Bali); Remote mountains have limited or no coverage. |
Country-by-Country Coverage Guide
Thailand
| RedEx Pricing | $10.99 for 6GB / 7 days |
| Best Networks | AIS, DTAC, TrueMove |
| Speed & 5G | 30-80 Mbps (City); 5G in Bangkok/Major cities |
Coverage notes: Bangkok and major tourist zones (Phuket, Chiang Mai) have excellent coverage. Rural Northeast is variable, and remote mountains like Pai have limited signal.
Data tips: Download offline maps for island hopping; 6GB is usually enough for a typical 7-day tourist usage.
Japan
| RedEx Pricing | $10.99 for 6GB / 7 days |
| Best Networks | NTT Docomo, SoftBank, au (KDDI) |
| Speed & 5G | 40-100+ Mbps; Excellent 5G in cities |
Coverage notes: Outstanding coverage even in rural areas and along Shinkansen routes. Tokyo and Osaka have top-tier 5G.
Data tips: Utilize extensive free WiFi in convenience stores (7-Eleven, Lawson) to save data.
Singapore
| RedEx Pricing | $10.99 for 6GB / 7 days |
| Best Networks | Singtel, StarHub, M1 |
| Speed & 5G | 50-150+ Mbps; 5G available almost everywhere |
Coverage notes: Full coverage across the island, including the MRT (subway) and Sentosa.
South Korea
Best networks: SK Telecom, KT, LG U+. Speed: 50-150+ Mbps with world-leading 5G. Full coverage in Seoul metro and subways.
Taiwan
Best networks: Chunghwa Telecom, Taiwan Mobile, FarEasTone. Speed: 30-80 Mbps. Excellent in Taipei; variable in mountain areas.
Vietnam
Best networks: Viettel, Vinaphone, MobiFone. Speed: 20-60 Mbps. Good in Hanoi and Ho Chi Minh City; Ha Long Bay has good coverage on boats.
Malaysia
Best networks: Maxis, Celcom, Digi. Speed: 20-60 Mbps. 5G growing in KL; variable in Borneo and Cameron Highlands.
Indonesia
Best networks: Telkomsel, Indosat, XL Axiata. Speed: 15-50 Mbps. Best in Java and Bali; limited in remote islands.
Philippines
Best networks: Globe, Smart. Speed: 15-40 Mbps. Good in Manila and Boracay; variable in Palawan.
Pricing Comparison: Asia eSIM Options
| Option | Estimated Cost | Best For |
|---|---|---|
| RedEx Single-Country | $10.99 (6GB / 7 days) | Single destination trips; 7-14 day vacations. |
| Multi-Country Regional | $25-$40 (5-10GB) | Multi-country circuits (e.g., Thailand → Vietnam). |
| International Roaming | $140-$210 (14 days) | Convenience, but very expensive. |
| Physical SIM Cards | $30-$60 (3 countries) | Budget travelers with time to find stores. |
Installation and Activation Guide
| Stage | Steps |
|---|---|
| Before Trip | 1. Purchase plan. 2. Install eSIM profile via QR code on WiFi. 3. Label the plan (e.g., “Japan Travel”). 4. Keep disabled until arrival. |
| Upon Arrival | 1. Enable the eSIM in Settings. 2. Wait 30-60 seconds for connection. 3. Test by loading a website. |
| Crossing Borders | If using separate plans: Turn off the old country eSIM and turn on the new one. Takes 2 minutes. |
Data Management for Asia Travel
WiFi Availability: Japan, Singapore, and South Korea have excellent free public WiFi. Southeast Asia (Thailand, Malaysia) has good WiFi in hotels and cafés. Vietnam, Indonesia, and Philippines are more variable.
Reducing Consumption:
- Download Google Maps offline (saves 200-500MB daily).
- Use hotel WiFi for video calls and streaming/downloads.
- Disable Background App Refresh in settings.
Special Considerations for Asia Travel
| Category | Tools & Apps |
|---|---|
| Messaging | Line (Thailand, Japan); WhatsApp (Singapore, Indonesia); KakaoTalk (S. Korea); Zalo (Vietnam). |
| Ride-Hailing | Grab (Most of SE Asia); Gojek (Indonesia); Bolt (Thailand). |
| Translation | Google Translate; Papago (Korean/Japanese); Pleco (Chinese). |
Troubleshooting & Itineraries
Thailand: Slow in islands? Manually select the AIS network. Japan: Some sites block foreign IPs; use a VPN if necessary. Indonesia: Telkomsel is usually the strongest network in Bali.
Example Itinerary: SE Asia Circuit (21 days)
Option: Individual plans for Thailand, Vietnam, and Cambodia cost around $32.97 total, saving money over a single regional plan and offering more total data (18GB vs 15GB).
Why RedEx eSIM for Asia Travel
RedEx eSIM offers consistent pricing ($10.99 for 6GB/7 days), partners with tier-one carriers like AIS and NTT Docomo, and provides 24/7 support. Compared to international roaming, you can save up to $188 on a two-week trip.