Tamil Bridge — தமிழ் பாலம்

Learn English and Hindi through Tamil. Voice teaching, sentence explanation, photo translation, any-language translation, dictionary, phonics, and the complete alphabet of all three languages.

Zero cost, permanently. No API keys, no subscriptions, no server required.

Moving to a new computer, or picking this up after a long gap? Read HANDOVER.md — what to install, where every account lives, how to make a change and put it live, and what to do if a service disappears.

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How to run — easiest first

1. Double-click (no install, nothing to set up)

Open index.html. That's it. The whole app runs in the browser.

2. One click, with a local server

Double-click Start Tamil Bridge.bat (Windows) or run ./start.sh (Mac/Linux). It starts a local server on http://localhost:5177 and opens it.

A server is slightly better than file:// because the browser gives it a stable origin, so your sign-in and history survive reliably.

3. Put it on the web (free forever)

See Deploying below.

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What it does

Feature	Notes
Translate	Any language → any language, translating as you type, like Google Translate. Auto-detect, swap, speaker on both sides, tap any word for its meaning.
Romanised typing	Type vanakkam → வணக்கம், namaste → नमस्ते. Dictionary-backed, so common words come out exactly right.
Meaning	cat → பூனை (pūṉai) / बिल्ली. Works from any language, and from romanised input (poonai). Part of speech, IPA, examples, synonyms, related words.
Sentence Explainer	Word-by-word gloss, part of speech, tense with its formula, subject/verb/object, and the SOV↔SVO word-order shift — explained in Tamil.
Spelling & grammar check	Targets the mistakes Tamil speakers actually make: missing articles, -s agreement, did went, a/an, plurals after numbers.
Voice teaching	The browser's own speech engine narrates lessons in Tamil and reads the target language slowly. Free, offline, no key.
Pronunciation practice	Speak into the mic, get a score per word with Tamil feedback.
Photo translate	OCR from a photo in 23 scripts (Tesseract.js), then translate.
Alphabet	Tamil all 247 (12 உயிர் + 18 மெய் + ஃ + 216 உயிர்மெய்), Hindi full varnamala + barakhadi, English A–Z with sounds.
Phonics	All 44 English phonemes with Tamil articulation notes, flagging the sounds Tamil does not have (/θ/ /f/ /v/ /z/ /æ/).
Vocabulary	201 words across 19 themes, each in Tamil / English / Hindi with romanisation, IPA, and the sound written in Tamil letters.
Lessons	10 graded units, 60 aligned sentences, grammar notes and quizzes.
Practice	Spaced repetition (SM-2), four directions, streaks and XP.
Accounts & history	Email or phone sign-in, every action logged, searchable, exportable.
Interface language	Tamil or English — the EN / த button in the top bar.

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Is it really free?

Yes, and here is exactly why — so you can verify it.

Part	What it uses	Cost
Voice (speak + listen)	Web Speech API, built into Chrome/Edge	free, no key
Translation	Google gtx endpoint → MyMemory → LibreTranslate → offline dictionary	free, no key
English definitions	dictionaryapi.dev	free, no key
Photo OCR	Tesseract.js (Apache-2.0) from a CDN	free
Fonts	Google Fonts, with Windows fonts as fallback	free
Storage	your browser's localStorage	free
Hosting (optional)	Vercel Hobby	free
Backend (optional)	Render free web service	free
Database (optional)	MongoDB Atlas M0	free forever

There is no paid tier and no account to create anywhere.

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Honest limitations

Worth knowing before you rely on it:

• It is not an AI / AGI. There is no language model. The tutor is a rules and dictionary engine: real grammar analysis, but deterministic. It will not handle an arbitrary complex sentence the way GPT-style models do.
• Sign-in is local by default. With no backend, your account lives in this browser on this device. Passwords are never stored — only a salted PBKDF2-SHA256 hash. Clearing browser data deletes it, so use Settings → Data → Download everything now and then.
• No password reset and no email/SMS verification. Both need a mail/SMS provider, which is not free at any meaningful volume.
• Translation and OCR need internet. Everything else — lessons, vocabulary, alphabet, phonics, practice, voice, the sentence explainer — works offline.
• Voices depend on your OS. If Tamil or Hindi sounds wrong or silent, install the voice: Windows → Settings → Time & language → Language & region → add the language → Speech.
• Speech recognition needs Chrome or Edge, and an internet connection.

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Deploying (free forever)

Frontend → Vercel

npm i -g vercel
vercel --prod

Vercel serves the repository root as a static site; .vercelignore keeps the server out of the deployment. Nothing to build.

Backend → Render (optional — only for syncing across devices)

The app is complete without this. Add it only if you want the same account on your phone and laptop.

1. Create a free MongoDB Atlas M0 cluster and copy its connection string. Do not use Render's own free Postgres — it expires after 30 days. Atlas M0 is free with no expiry.
2. Push this repo to GitHub, then in Render: New → Blueprint, pick the repo. render.yaml configures everything.
3. Set these in the Render dashboard:
   • MONGODB_URI — your Atlas string
   • ALLOWED_ORIGIN — your Vercel URL, e.g. https://tamil-bridge.vercel.app
   • JWT_SECRET — generated automatically
4. In the app: Settings → Sync, paste the Render URL, press Test connection.

This is the beginning of the README. Read the rest at the original. Read the full README ↗