Open Source Alternative to Slowly: LangX vs Slowly (2026)
LangX is an open source alternative to Slowly for people who want to practice a language with pen pals: a free language exchange app with public code (BSD-3), two-way matching and corrections on any message, unlimited on every plan. The honest difference is pace. Slowly delivers anonymous letters that take hours or days to arrive, which is lovely for thoughtful writing; LangX is a fast one-to-one chat built to teach, so it suits you better if you want daily practice and feedback.
Everything about Slowly below comes from its app store listings, its own site and reputable reviews at the time of writing (September 2026).
LangX vs Slowly at a glance
| LangX | Slowly | |
|---|---|---|
| Format | Instant one-to-one chat | Letters delivered with a delay based on distance |
| Pace | Minutes, as fast as you both reply | From about half an hour to a few days per letter |
| Matching | Two-way: you only see people who speak what you learn and learn what you speak | Auto-match by interests, or browse by topics, region and languages with a proficiency level |
| Corrections | Hold any message to correct it; unlimited on every plan | No correction tools; it is not a learning app |
| Translation | Built into the chat; 20 a day on Free, 300 on Fluent, 1000 on Polyglot | Not a listed feature; you look words up yourself |
| Voice and calls | Voice, photo and video messages; read-aloud; no live calls | Written letters, plus audio notes and photos when both sides agree; no calls |
| Identity | Profile with your languages, usually with photos | Nickname and avatar, no real names or photos required |
| Free plan | Yes: unlimited replies and corrections, 5 new conversations a day | Yes: unlimited letters, with a quota on friends |
| Paid plan | Yes: Fluent and Polyglot | Yes: Slowly Plus, plus Slowly Coins for stamps |
| Ads | None | Google Play lists the app as containing ads (you can watch short ads to earn coins) |
| Open source | Yes, BSD-3, self-hostable | No |
| Platforms | iOS, Android, web | iOS, Android, web |
| Community size | Small and growing | Much larger; 5M+ downloads on Google Play |
Table: LangX vs Slowly, the open source alternative to Slowly compared feature by feature (September 2026).
What Slowly does well
Slowly is one of the most loved pen-pal apps around, and any honest Slowly alternative page should start by saying why.
- The slowness is the point. Slowly was launched in 2017 by a small team in Hong Kong. Each letter “travels” at a speed that reflects the real distance between you, so a letter to a neighboring country might arrive in hours and one to the other side of the world in a couple of days. There is no pressure to answer instantly, and people write accordingly.
- Long, thoughtful letters. Because a reply takes time anyway, Slowly users tend to write real letters rather than one-line messages. For an intermediate or advanced learner, reading a full page from a native speaker and writing one back is excellent reading and writing practice.
- Privacy by design. You use a nickname and an avatar. Slowly’s own listing says no photos and no real names are needed, and photos or audio notes are only shared once both people agree. Many introverts find this far less stressful than a chat app.
- Stamps and small joys. Slowly has more than 2,000 collectible stamps from around the world. You get some free on special occasions, and others come from the Stamp Store using Slowly Coins, which you can buy or earn by watching short ads.
- Language settings that work. You can list your languages with a level from “Interested” through “Fluent” and “Native”, and filter pen pals by language, topics and region. Plenty of members write in a second language on purpose.
- Free at its core. Slowly says letters are unlimited and free. Slowly Plus, the paid membership, doubles quotas such as the number of friends, excluded topics and regions and photo sharing, and lets you visit a pen pal’s local Stamp Store.
If you love letters, want anonymity, and are happy to wait for a reply, Slowly is hard to beat.
Where LangX differs from Slowly
LangX makes nearly the opposite trade-off. It is built around fast, frequent practice with someone who is learning your language in return.
An open source alternative to Slowly
The LangX app and API are public on GitHub under the BSD-3 license. You can read the code, see what the app sends, contribute, or host your own instance. Slowly is closed source. If transparency matters to you, that is the main reason to look for an open source alternative to Slowly.
Corrections are the core, not an extra
Slowly is a pen-pal app first. It has no correction tool, so if a pen pal wants to fix your grammar they have to rewrite your sentence in their own letter, and you might see it days later. On LangX you hold any message to correct it, and the fix shows up in the chat right away. Corrections are unlimited on every plan, Free included, and so are replies to anyone who writes to you.
Two-way matching instead of shared interests
Slowly matches you mostly on interests, which makes for good friendships but not always a fair exchange. LangX’s Discover only shows people who speak the language you are learning and are learning a language you speak, so both of you have a reason to help. If the idea is new to you, what is a language exchange explains why that balance matters.
Fast feedback beats slow feedback for most learners
Seeing a mistake corrected while you still remember writing it helps it stick. A letter every few days is wonderful for friendship, but it gives you only a handful of chances a week to write, get feedback and try again. A chat lets you do that dozens of times in one evening. Our post on why consistent practice is key goes into why frequency matters.
Translation and read-aloud inside the chat
LangX has translation built into the chat (20 a day on Free, 300 on Fluent, 1000 on Polyglot) and can read any message aloud so you hear how it sounds. With letters you look words up yourself, which some learners actually prefer for reading practice.
No ads
LangX shows no ads and uses no advertising identifiers. It does have product analytics (PostHog on its EU cloud, including a masked screen recording on iOS and Android where every word and image is replaced by a grey block on the device). It is on by default and switches off in Settings → Privacy → Share usage data; the privacy policy lists exactly what is sent. One honest point in Slowly’s favor: LangX profiles usually show photos, while Slowly lets you stay behind an avatar.
Is LangX a free Slowly alternative?
Yes. LangX Free includes unlimited text messages, unlimited replies and corrections, 5 new conversations a day and 20 translations a day, with no ads. Fluent and Polyglot add unlimited new conversations, more translations, more languages on your profile and extra filters; see the plans page. Prices are set per region and shown in the app.
Slowly is free too, so price is not a reason to switch. The real reasons are speed, corrections, two-way matching and open source.
LangX vs Slowly: who should pick which?
Pick Slowly if you:
- love writing and reading long letters
- want to stay anonymous, with no photos
- enjoy the anticipation of a reply and collecting stamps
- are mainly looking for friendship, with language practice as a bonus
Pick LangX if you:
- want an open source alternative to Slowly you can audit or self-host
- want to practice every day and get corrections right away
- want every partner you see to be a two-way match
- want translation and read-aloud inside the conversation
Or use both. Some learners keep one or two Slowly pen pals for long letters and use a chat app for daily practice. If you are nervous about chatting in real time, an introvert’s guide to learning a language and our list of language exchange conversation topics make the first messages easier.
Other Slowly alternatives
Looking at other apps like Slowly? Each has its own comparison:
- InterPals: a long-running pen-pal website and app, free and ad-supported, good for slower, longer messages. See LangX vs InterPals.
- ConversationExchange: a simple site for finding partners to write to, chat with or meet in person. See LangX vs ConversationExchange.
- HelloTalk: a big, busy exchange app with a social feed, voice rooms and calls. See LangX vs HelloTalk.
- Tandem: a large exchange app with text, voice and video calls. See LangX vs Tandem.
The best language exchange apps roundup compares them all in one place.
FAQ
What is the best open source alternative to Slowly?
LangX is an open source alternative to Slowly for language practice. Its app and API are public under the BSD-3 license and can be self-hosted. It swaps delayed letters for fast one-to-one chat with two-way matching and unlimited corrections.
LangX vs Slowly: which is better for learning a language?
For regular practice and feedback, LangX, because corrections, translation and read-aloud are built into the chat and replies come in minutes. For long-form reading and writing with no time pressure, Slowly is excellent.
Is there a free Slowly alternative with no ads?
LangX’s Free plan has no ads and includes unlimited replies and corrections, 5 new conversations a day and 20 translations a day.
Can I use Slowly for language exchange?
Yes. Slowly lets you list your languages and levels and filter pen pals by language, and many members write in a language they are learning. It just has no learning tools such as corrections or translation, so it works best for learners who can already write a letter.
What are other apps like Slowly?
InterPals and ConversationExchange are the closest apps like Slowly for pen-pal style writing. HelloTalk, Tandem and LangX are faster, chat-based language exchange apps. The compare page lists every LangX comparison.
More comparisons: all comparisons · LangX vs InterPals · LangX vs ConversationExchange · LangX vs HelloTalk · LangX vs Tandem · best language exchange apps