Open source Telegram bots

High-scale contest bot with a "Boost on Luck" mechanic: up to 100 winners, votes increase chances. Free, open source, 2.9 million monthly users.

The best-known standalone captcha bot for Telegram groups: button, math or custom question on entry, kicks whoever fails. Free, open, 207 thousand monthly users.

All-in-one scanner and generator: point it at a photo to decode QR codes and a dozen barcode formats (UPC, EAN, Code 128 and more), or send text to create a new QR code. Free, open source, interface in nine languages including Russian.

A text-to-speech bot with over 2,500 voices and HD audio quality in Russian and English, powered by the open-source Silero speech-synthesis project.

International, open-source captcha bot: image or math verification for new group members. Free, multilingual, 18 thousand monthly users.

Open-source RSS-to-channel bot: subscribe to any feed and new items post automatically, formatted for readability. Free, self-hostable.

A Mini App scanner that uses the phone camera through Telegram itself: point, scan, and the decoded URL, vCard, Wi-Fi or text appears instantly, with history synced to your account.

Transcribes voice messages and video notes to text in private chats and groups: forward a voice or add Voicy to a chat and every voice message gets a text reply. Free, open source, many languages.

The GitLab half of Notifine, an open-source notification bridge (also covering GitHub and Trello) that posts pushes, merge requests and pipeline events into Telegram. Free, source on GitHub, built in Rust for reliability.

An open-source bot that moderates the Werewolf social-deduction game in Telegram groups, tracking roles, votes and night actions automatically. Free, roughly 87,000 monthly users.

A no-frills unit converter — type something like "100 ft to m" and get an instant answer covering length, area, volume, weight, temperature, energy and speed. Free and open source.

Open-source checklist bot: send a multi-line message and every line becomes a tappable checkbox item. Works in a private chat or as a group/channel admin. Free.

A free bilingual OCR bot built on the open-source Tesseract engine - extracts text from a photo in both Russian and English descriptions.

An open-source flashcard bot for Chinese: build your own word deck (or import ready-made HSK 1–6 lists), drill pronunciation, translation and writing, and get pinyin tones highlighted by color.

Inline currency converter: type @currconverter_bot 20 eur in usd in any chat to drop a converted amount straight into the conversation, using mid-market rates. Free, English, no group add needed.

A 2FA authenticator inside Telegram — generates time-based one-time codes (TOTP), the same kind Google Authenticator produces, so you don't need a separate app for two-factor login.

One job, done well: turns a Wi-Fi network name and password into a scannable QR code so guests connect with a camera tap instead of typing a long password.

Open-source bot that checks whether a website is up right now, or keeps tracking a URL and pings you the moment it goes down. Free, no sign-up, source code published on GitHub.

Search and share books from Goodreads right inside any chat via inline mode — title, author, cover and a "read more" for the description and average rating. Free.

An open-source bot that converts between Telegram's own message types — turning a file into a voice, video, photo or sticker message and back, with the source code public on GitHub.

A password generator built by an individual developer (halltape) whose companion project on GitHub is a "Telegram bot for password generation and verification" — the code itself is publicly viewable.

The GitHub half of the same open-source Notifine project as gitlab_notifine_bot: pushes GitHub repository events into Telegram via a webhook. Free, source on GitHub.

An open-source Telegram bot that shortens any link using five different shortening services and works in inline mode, so a short URL can be created from inside any chat without switching apps.

A minimal open-source stock ticker bot: query a symbol and get its price. Documented on GitHub; the bot's own message mentions a sponsor option for full access. English.

An open-source disposable-email bot whose entire codebase is public on GitHub: create up to 8 throwaway addresses, read mail in Telegram, no ads and no password — just an unusually auditable temp-mail option.

Multiple-choice polls that native Telegram polls historically didn't support: create a poll where people can pick more than one option, and share it. Free.

An open-source resizer purpose-built for one job: preparing images to the exact 512px specs Telegram sticker packs require, with the code published on GitHub.

An unofficial bridge from Telegram to Evernote: send text, photos or voice and the bot saves each message as a note in your Evernote account. Free, requires linking Evernote.

An open-source Turkish practice bot: translate words between Turkish, Russian and English, get a word of the day, and see morphological breakdowns of the words you're learning.