Lemonfox TTS at $2.50 per million characters vs Sume: the honest gap

Lemonfox.ai prices text-to-speech as $0.50 per 1 million credits, where 200,000 characters of TTS count as one credit batch's worth; the page's free plan reads 10 million credits for 2 million characters (read 2026-10-06). That works out to about $2.50 per million characters, derived from those two figures; the page does not print a per-character rate itself.

Sume TTS 1.0 lists at $47.50 per million characters ($0.0475 per 1,000), 19 times that. For a buyer typing "cheapest text to speech API", Lemonfox is cheaper by a wide margin and this post will not pretend otherwise.

The arithmetic

What you pay the difference for

At 22,500 characters, about thirty 750-character shorts, the gap is under a dollar either way. Whether that is worth paying depends on what you need around the audio.

Sume gives you asynchronous jobs with ids, webhooks, an idempotency key and, for scripts accepted through the source API, a server-owned transcript_receipt that proves which sentences were read. The Lemonfox page does not describe equivalents. Sume voices come with a language tag and a mismatch warning (409 tts_voice_language_mismatch) that stops a charge before it happens.

If the whole requirement is the lowest bill for plain audio from text, take the cheaper vendor. Sume's value is in the pipeline around the audio, plus having TTS next to video, captions and timeline tools in one workspace.

A cheap-vendor check before you commit

• Does it return a job id and let you poll or take a webhook?
• Can you prove which words were spoken?
• What does it do with a voice whose language does not match the text?
• What is the maximum request size? Sume accepts 20,000 characters in one job.