Eleven v4 covers 90+ languages. Check your language on Sume TTS first

The counts

ElevenLabs' Eleven v4 post (read 2026-10-04) says the model supports 90+ languages. Cartesia's Sonic documentation (read 2026-10-04) lists 44 languages for Sonic 3.6, and Sume's POST /v1/tts-router/generate calls the Sonic models. So if your language is outside the 44, test before you plan around Sume TTS.

Counts do not guarantee quality. A language can be listed and still sound uneven on names, numbers or dialect, so a 20-second test beats a count.

The comparison

The numbers are from the vendors' own pages. The last row is the test, which only you can run.

How to test a language on Sume

Take a typical paragraph in your language, with a name, a number and a date in it. Choose a voice that speaks the language, and send the text with language set to its ISO code. If the voice and language disagree, Sume returns a mismatch warning, and confirm_language_mismatch lets you confirm on purpose; read the warning before you do, because it usually means the wrong voice.

Compare the result against a native speaker's reading. Listen for stress on names, how numbers are read, and whether punctuation produces natural pauses. Run the check on two voices, since one voice can fail where another is fine.

What to do when the language is not covered

Do not force an unsupported language through an English voice; the result is usually unusable. Use a vendor that lists your language, and note that moving the text between vendors is easy when your script is plain text and your voices are named in one config file. Sume's transcript field takes plain text, so a script written for one engine moves to another without conversion.

• Test at least 100 words, not a greeting.
• Try a second voice before you decide.
• Set language explicitly rather than relying on guesses.
• Re-read the vendor language page on the day you commit.

A short test script

Write the test text once in your language and keep it. Include a greeting, a price with a currency symbol, a date, a product name in Latin letters and a closing sentence with a question. Those five patterns catch most problems. Generate it on each candidate service at the same speed and listen back to back. The cost of the test on Sume is small: 400 characters is 0.4 x $0.0475 = $0.019.

Keep the file and the notes. When a vendor adds languages or ships a new model, repeat the same test and compare against your saved result.