Best Pen Pal Apps in 2026: 7 Apps and Sites Compared
By Liebeastra
The best pen pal app depends on how slow you want it. Slowly is best for letters that take hours or days to arrive. InterPals is the biggest free pool, with 8.5 million users by its own count. Bottled is for random messages to strangers. HelloTalk and Tandem are for language practice. Postcrossing is for real postcards. penfolk is for pen pals who share your interests, music and languages.
I build penfolk, so I'm one of the options here. I tried to write the comparison I'd want to read anyway. Facts come from each app's own site or its US App Store listing, checked in November 2026. Prices change per country, so check the store before you pay.
Pen pal apps compared
| App | How it works | Price | Best for |
|---|---|---|---|
| Slowly | Letters that arrive hours to days later, based on distance. Avatars, no photos | Free letters, optional Slowly Plus | Long letters and a slow pace |
| InterPals | Search by country, language or interests and message people. Website and app | Free | A large free pool of people |
| Bottled | Each message goes to one random stranger, who can reply or throw it back | Free, with in-app purchases | Writing to someone completely random |
| HelloTalk | Chat with translation and corrections, plus a public feed | Free, VIP $12.99/month or $79.99/year | Language practice with lots of partners |
| Tandem | 1-to-1 chat and calls, every member reviewed first | Free, Tandem Pro (12 months listed at $69.99) | Speaking practice in a screened community |
| Postcrossing | Send a real postcard, get one back from a random member | Free to join, you pay postage | Real mail without a long commitment |
| penfolk | Messages, with profiles that show what someone listens to and which languages they speak | Free, optional $2.99/month supporter tier | Pen pals you actually have things in common with |
Slowly
Slowly is what most people picture when they think of a modern pen pal app. You write a letter and it travels: a few hours if your pen pal is nearby, a few days if they live on the other side of the world. Profiles use avatars instead of photos, and you collect stamps from different places as you go. Sending and receiving letters is free, and Slowly Plus is an optional in-app purchase.
Good: the waiting makes people write properly. Less good: if you click with someone and want to keep going, the delay can feel long. I wrote about the options in apps like Slowly.
InterPals
InterPals has been around since 1998 and says it has 8.5 million users in 180+ countries. You search for people by country, language or interests and message them. It's free. If you want a pen pal from one specific country, the size helps.
Good: huge, free, and you can search precisely. Less good: it's a busy inbox, so a thoughtful first message matters. More in InterPals alternatives.
Bottled
Bottled works like a message in a bottle. You write something and it goes to one random person somewhere. They can keep it and reply, or throw it back into the sea. It's free on iOS and Android, with in-app purchases.
Good: a fun way to reach someone you'd never have found. Less good: you don't choose who reads it, so it's more luck than matching.
HelloTalk
HelloTalk is a language exchange app with a lot of pen pal energy. You chat by text, voice or video, with translation and corrections built in, and there's a public feed called Moments. HelloTalk says it has 70M+ learners. VIP costs $12.99 a month or $79.99 a year on the US App Store.
Good: you'll find a partner for almost any language. Less good: it's fast and busy, closer to social media than to letters.
Tandem
Tandem focuses on 1-to-1 conversation: text, voice notes and calls. It reviews every application before you get in, which keeps things calmer but can mean waiting. The core app is free, and the US App Store lists a 12-month Tandem Pro plan at $69.99.
Good: a screened community, strong for speaking practice. Less good: the approval wait, and it's more about practice than long letters.
Postcrossing
Postcrossing is for paper. You request an address, send a postcard to a random member, and a random member sends one to you. Its stats page lists more than 800,000 members in 207 countries. Joining is free, but every card costs you a stamp.
Good: real mail in your letterbox. Less good: it's one card per person by design, so ongoing friendships happen off to the side.
penfolk
Mine, so weigh this accordingly. penfolk is built around the moment before you write. Profiles show the languages someone speaks and learns, their music if they connect Spotify or Last.fm, Top 3 lists of albums, films or books, and where they're travelling next. The Partners view ranks people by matching languages and shared interests, so you have something to say beyond "hi".
Messages arrive instantly, but there's no pressure to answer quickly, and the feed is chronological by default. You can send voice notes, translate a message and leave inline corrections, which helps if your pen pal is also your language partner.
The honest limits: penfolk is a lot smaller than InterPals or HelloTalk. There are no video calls and no letter delivery delay like Slowly has. Free accounts can start 10 new conversations a day, and there's an optional $2.99/month supporter tier.
Which pen pal app should you pick?
- You want the letter ritual and don't mind waiting: Slowly.
- You want the biggest free pool: InterPals.
- You want to write to a total stranger and see what happens: Bottled.
- You mainly want language practice: HelloTalk or Tandem.
- You want something in your real mailbox: Postcrossing.
- You want a pen pal who shares your taste in music, books or travel: try penfolk.
New to all this? Start with how to find a pen pal, and if you're stuck on what to say, use these pen pal letter ideas.
FAQ
What is the best free pen pal app?
InterPals is free and has the biggest pool. Slowly is free to send and receive letters. penfolk is free with an optional supporter tier. HelloTalk and Tandem have free versions with paid upgrades.
Is there a pen pal app for adults?
Yes. Slowly, InterPals, HelloTalk, Tandem and penfolk all have adult members. Read each app's age rules when you sign up, because they differ.
Is there a letter writing app like Slowly?
Slowly is the main app with delayed letter delivery. For paper letters, Postcrossing and Global Penfriends are the closest. For slower messages with richer profiles, penfolk.
Which pen pal app is best for learning a language?
HelloTalk and Tandem have the most language tools inside the chat. penfolk matches you on languages and shared interests and has translation and inline corrections in messages.
Are pen pal apps safe?
Most have blocking and reporting. Keep personal details like your address and full name to yourself until you trust someone, and never send money to a pen pal.