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

Croatian gets exactly one neural voice in this product, and it only runs on a GPU — everyone else gets the voice their phone or laptop already has. Paste Croatian 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 Croatian (Hrvatski), which ones silently do not, and what each one costs you.

Which engines actually speak Croatian

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.

Only one of Quick TTS's three neural engines speaks Croatian, and it is worth being blunt about the other two:

• Piper ships zero Croatian voices. The upstream Piper catalogue has no Croatian model at all — there is no hr_HR-* voice to load, so offering the engine on this locale would just fail at selection time. The option is hidden on Croatian rather than shown and then breaking.
• Kokoro-82M is English-only and is hidden everywhere else, Croatian included.
• Supertonic HD does speak Croatian, natively, at 44.1kHz, as one of the 31 languages this model covers.

That is the same one-engine position Korean and Japanese are in. The difference is what it costs to reach that one engine: Supertonic is WebGPU-only, with no WebAssembly fallback tier, which makes it a desktop-class feature in practice. For anyone on a phone, or an older laptop without a discrete GPU, the honest answer isn't the HD engine — it's the Web Speech API, using whatever Croatian voice the device already ships.

The honest limits

Supertonic HD is WebGPU-only by design — there is no WASM tier under it the way there is for Piper. Measured WASM real-time factor for this model is close to 0.89 even on strong desktop CPUs, which is barely usable, so a slow fallback was never shipped. That means: no WebGPU, no neural Croatian voice, full stop. Phones fall back to Browser TTS and whatever Croatian voice their OS provides — on Windows that is Microsoft Edge's online neural voices (Gabrijela and Srečko), not a classic offline SAPI voice, since Windows has never shipped one for Croatian. There is no Piper safety net underneath any of this the way other supported languages get.

Croatian spelling doesn't mark vowel length or pitch accent, both of which are phonemic — two words can be spelled identically and differ only in how long a vowel is held or which syllable carries rising versus falling pitch, a distinction native speakers hear immediately and that no TTS engine reconstructs from plain text. A second, more mundane failure mode is diacritics: text typed without them collapses č, ć, and sometimes đ down to a bare c or d, and a TTS engine reading that flattened spelling will not silently recover the missing marks the way a human reader does from context.

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 Croatian 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 Croatian documents, not just pasted text

PDF, DOCX, EPUB, ODT, RTF, HTML, TXT and Markdown are all parsed in the browser, so a whole Croatian 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 Croatian text-to-speech free?

Yes. Quick TTS reads Croatian 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 Croatian 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 Croatian TTS voice in the browser?

Supertonic HD is the highest-quality Croatian voice available here — 44.1kHz, running on WebGPU. It is also the only neural Croatian option: Piper ships no Croatian voice and Kokoro is English-only, so the alternative is your operating system's built-in voice. To get Croatian voices rather than English ones, open the app at quick-tts.com/hr/ — 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 Croatian 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 Croatian — open the Hrvatski 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 Croatian text pasted there will be pronounced as though it were English. Open the Hrvatski version instead and the engine picks up Croatian 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 Croatian and part English.

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.