secure messaging app · LY Corporation

LINE

Free messenger with default end-to-end encrypted chats, but calls in groups are not covered.

42/100

#11 of 12 secure messaging apps
Facts checked 8 Oct 2026

In short

LINE's basic features are free to use⁵.
Letter Sealing, its end-to-end encryption, is on by default and cannot be turned off².
Group voice and video calls are outside Letter Sealing; only one-to-one calls are covered².
A group holds up to 500 members, or 100 when members join automatically⁶.
In Hong Kong, Japan, Korea, Taiwan and Thailand, signing up needs phone number verification³.

LINE suits people who need a free messenger that their contacts already use, with encrypted chats on by default^2,5. It has desktop apps for Windows and Mac and groups of up to 500^4,6. The catch: group calls are not end-to-end encrypted, chat encryption is documented only for groups of up to 50, and sign-up needs a phone number in LINE's main markets^2,3,7.

Best for: People who chat with contacts in Japan, Taiwan or Thailand.

Where the points come from

Encryption12 of 20

Source and audits0 of 26

Sign-up and identity12 of 16

Chats and calls2 of 14

Systems8 of 16

Price8 of 8

Encryption 12 of 20 points

Rule	What is published	Points
End-to-end encrypted by default	YesLetter Sealing is on by default and cannot be disabled; it covers 1-to-1 chats and group chats of up to 50 members^2,7.	12 / 12
Post-quantum key exchange	Not publishedNot found in the vendor's pages or its 2024 encryption report^2,7.	0 / 4
Encrypted backups	NoThe 2024 encryption report says messages are not end-to-end encrypted when a third-party cloud backup is used⁷.	0 / 4

Source and audits 0 of 26 points

Rule	What is published	Points
Open-source apps	Not publishedNot published on the vendor's pages^1,2.	0 / 8
Independent audit since 2022	Not publishedNo named outside auditor in the vendor's pages or its 2024 encryption report^2,7.	0 / 10
Public bug bounty	NoLY Corporation's bug bounty page says the programme was suspended on December 3, 2025 and pays no rewards after that date⁸.	0 / 4
Transparency report	Not publishedNot found on the LINE pages read^1,2.	0 / 4

Sign-up and identity 12 of 16 points

Rule	What is published	Points
No phone number needed	YesOutside Hong Kong, Japan, Korea, Taiwan and Thailand, sign-up uses an Apple or Google account with no phone number step; those five countries need one³.	12 / 12
Contacts by username	Not publishedNot published on the vendor's pages³.	0 / 4

Chats and calls 2 of 14 points

Rule	What is published	Points
Disappearing messages	Not publishedNot published on the vendor's pages^2,5.	0 / 5
Largest group chat	500Up to 500 members including the creator; 100 when members join automatically⁶.	2 / 4
Encrypted voice and video calls	NoOne-to-one calls are covered, but group voice and video calls use only transport-layer encryption².	0 / 5

Systems 8 of 16 points

Rule	What is published	Points
Apps	Windows, macOS, iOS, AndroidHelp article offers LINE for Windows or Mac; home page links iOS and Android. LINE for Chrome is an extension^1,4.	8 / 12
Windows works without the phone	Not publishedNot published on the vendor's pages; first login needs a code entered on the main phone⁴.	0 / 4

Price 8 of 8 points

Rule	What is published	Points
Cost for one person	$0Basic features are free to use⁵.	8 / 8

The rule behind each line: how we score secure messaging apps.

Plans and prices

As the vendor lists them, before tax. Prices are in US dollars unless the plan shows euros; the points use US dollars, with euros converted at the ECB rate.

Plan	Price as listed	Per month	Notes
LINE1 person	Free⁵	$0	Basic features free; mobile data fees may apply

Paid items such as stickers, emoji and Coins are listed in LINE's help centre and are not counted; mobile data fees may apply⁵.

Strengths

Letter Sealing is on by default, with no option to disable it².
Basic features are free⁵.
Groups can reach 500 members⁶.
Desktop apps exist for Windows and Mac, with email and password login⁴.

Limits

Group voice and video calls, meetings, albums and notes are not covered by Letter Sealing².
Letter Sealing is documented for group chats of up to 50 members, while groups can reach 500^6,7.
Photos, videos, voice messages and files may be unencrypted, depending on version².
Phone number verification is required in Hong Kong, Japan, Korea, Taiwan and Thailand³.
A first PC login needs a code entered on your main phone⁴.

Other secure messaging apps

1
SimpleX ChatPeople who want a messenger that holds no account identifier or phone number
86/100
$0cost for one person
2
ThreemaPeople who want a messenger with no phone number and no subscription
79/100
$6/yrcost for one person
3
WirePeople who want default encryption and open-source apps without handing over a phone number
78/100
$0cost for one person
4
ElementPeople who want open-source apps on every platform and no phone number
69/100
$0cost for one person

All 12 secure messaging apps

Sources

LINE, LINE. Accessed 8 Oct 2026.
About Letter Sealing, LINE Help Center. Accessed 8 Oct 2026.
Creating a new LINE account, LINE Help Center. Accessed 8 Oct 2026.
How to download, log in, and log out of LINE on a PC, LINE Help Center. Accessed 8 Oct 2026.
Can I use LINE for free?, LINE Help Center. Accessed 8 Oct 2026.
Creating, joining and inviting others to groups, LINE Help Center. Accessed 8 Oct 2026.
LINE Encryption Report (2024), LY Corporation. Accessed 8 Oct 2026.
LINE Bug Bounty, LY Corporation. Accessed 8 Oct 2026.

Website: line.me · Markdown version · We are not affiliated with LY Corporation.