Korean Text to Speech: Free, In-Browser, Nothing Uploaded

Korean is the clearest case in this whole product of a language where one engine carries everything. Paste Korean text, press play, and the audio is generated on your own device — no account, no upload, no character limit. This page is the honest version: which engines really speak Korean (한국어), which ones silently do not, and what each one costs you.

Which engines actually speak Korean

Quick TTS ships four TTS engines and lets you switch between them from one dropdown — but not all four cover every language, and the gaps are not the ones you would guess from the marketing.

Two of Quick TTS's three neural engines cannot speak Korean at all, and it is worth being blunt about which:

• Piper ships zero Korean voices. This is not a Quick TTS limitation — the upstream Piper voice catalog has no Korean model, so there is nothing to load. The Piper option is hidden on Korean rather than offered and then failing.
• Kokoro-82M is English-only. It is hidden outside English for the same reason: recommending it for Korean would be recommending a voice you cannot select.
• Supertonic HD does speak Korean — natively, at 44.1kHz, as one of the fifteen languages this build maps.

So for Korean there is exactly one neural option in the browser, and it is the best one of the three. That is a genuinely unusual position: on most languages the neural tier is a compromise between quality and device support, and on Korean it simply isn't — you either get studio-grade 44.1kHz or you get your operating system's built-in voice.

The honest limits

The honest cost of that: Supertonic is WebGPU-only, with no WebAssembly fallback tier. Piper covers GPU-less machines in other languages; in Korean there is nothing behind Supertonic but the Web Speech API. Measured WebAssembly speed for this model is barely realtime even on strong desktop hardware, so a WASM tier would be a worse experience than the system voice it would be replacing — it is left out on purpose rather than shipped and disappointing.

In practice that means: desktop Chrome or Edge with a working GPU gets HD Korean; a phone, a Safari session, or an office machine with GPU acceleration disabled gets the Web Speech API, which on a modern iPhone or a Korean Windows install is a decent built-in voice and needs no download at all.

Korean also exercises the chunker differently from European languages: Quick TTS splits CJK text at 120 characters rather than 300, because a Korean character carries far more speech per character than a Latin one and the larger window would produce audibly long generation stalls.

Nothing you paste is uploaded

This is the part that separates in-browser TTS from the cloud tools that look identical in a browser tab. A cloud tool sends your Korean text to a server, synthesizes it there, and sends audio back — the page is a remote control. Quick TTS ships the engine to you instead and runs it on your CPU or GPU, so your text is never received by anyone. The test is simple: once the page and its model have loaded, the neural engines keep working with your network disconnected.

That matters most for the documents people actually want read aloud — a contract, a medical letter, coursework, an unpublished draft. It also means there is no "we phonemize non-English text on our server" asterisk, which is not true of every tool advertising local synthesis.

Reading Korean documents, not just pasted text

PDF, DOCX, EPUB, ODT, RTF, HTML, TXT and Markdown are all parsed in the browser, so a whole Korean EPUB or a long PDF opens and plays without a byte leaving your machine. A scanned PDF — a photo of text with no text layer — is handled by running OCR locally in WebAssembly rather than uploading the scan, which is precisely the case where local processing is worth the most.

Speed, volume and voice can all be changed mid-read and the current passage replays under the new settings without starting over. Switching the engine itself stops playback, so you press play once to start the new one — there is no mid-read handover of the remaining text between engines.

Frequently asked questions

Is Korean text-to-speech free?

Yes. Quick TTS reads Korean with no account, no character limit and no watermark. Synthesis runs in your browser on your own device, so there is no per-character server cost to meter and nothing to gate behind a sign-up.

Is my Korean text uploaded anywhere?

No. The speech engine ships to your browser and runs locally, so the text you paste is turned into audio on your machine and never sent to a server. That is an architectural property, not a promise in a privacy policy — there is no server in the loop once the page has loaded.

What is the best Korean TTS voice in the browser?

Supertonic HD is the highest-quality Korean voice available here — 44.1kHz, running on WebGPU. It is also the only neural Korean option: Piper ships no Korean voice and Kokoro is English-only, so the alternative is your operating system's built-in voice. To get Korean voices rather than English ones, open the app at quick-tts.com/ko/ — the neural voice list follows the page language.

Does it work on a phone?

The Web Speech API engine works on every modern phone with no download, and it is the default so the first play click always works. The neural engines are more demanding: Supertonic HD needs WebGPU and is effectively a desktop feature.

Can I download the Korean audio?

Yes, as WAV or MP3, generated on your device. Anything longer than about 20,000 characters is packaged as a ZIP of audio parts so memory stays bounded on long documents.

Try it in Korean — open the 한국어 app, not the English one

This is the one piece of setup worth knowing, because it is not obvious: the neural voice list follows the language of the page you are on. On the English homepage the Supertonic reads with the English language tag — so Korean text pasted there will be pronounced as though it were English. Open the 한국어 version instead and the engine picks up Korean automatically.

The one exception is Supertonic's "Auto language" toggle, which switches generation to a language-agnostic mode that reads mixed-language text with the right pronunciation per language without tagging anything by hand. That works from any page — it is the right choice for a document that is part Korean and part English. For which voice to pick once you are there, the Korean-language voice guide goes deeper.

For the architecture behind all of this, see how in-browser text-to-speech works; for a tool-by-tool comparison with the other local TTS sites, see the comparison page.