Per-Character Pricing: Examples & Companies

What is it

Per-Character Pricing is a billing unit where customers are charged per character of text processed — the standard meter for text-to-speech and translation. The vendor bills the text going in, not the audio coming out: a 10,000-character script costs the same whether the voice reads it in six minutes or eight, which makes the unit fully countable before a single second of audio is generated.

The text-to-speech cluster carries the unit most directly. LMNT sells character allowances (200K on the $10 Indie tier, 5.7M on the $199 Premium) with per-1,000-character overage that falls from $0.05 to $0.035 as tiers climb; Hume AI ladders Octave TTS from 10K free characters to 10M on its $500 Business tier with overage descending from $0.15 to $0.05 per 1,000; PlayHT sold ~3M characters a year on its Creator plan with $4-per-10,000 overage until Meta’s July 2025 acquisition wound the product down. ElevenLabs and Hedra meter the same unit one abstraction up, through credits — Hedra’s wallet prices speech at exactly 15 credits per 1,000 characters alongside per-second video.

Beyond TTS, the character shows up wherever text volume is the cost driver: Speechmatics bills its TTS per character beside per-hour speech-to-text, Unbabel’s Widn.ai caps free translations at 1,500 characters each, and Rytr gates its free writing tier at 10,000 characters a month before flat “unlimited” plans take over.

How it works

The standard structure is a subscription allowance plus metered overage: bill = tier fee + max(0, characters − included) × rate per 1k. The levers:

Worked example — pricing an audiobook. A 90,000-word manuscript is roughly 500,000 characters. On LMNT Pro ($49, 1.25M included) it fits inside the allowance — effective cost $49. On Hume AI Starter ($3, 30K included) the same job runs ~470K characters of overage at $0.15/1k ≈ $73.50, while on Hume’s $70 Pro tier it fits in the 1M allowance. The unit is identical; the tier choice moves the bill by 25x — which is why the usage-metric guide treats allowance-sizing, not the headline rate, as the real comparison. You can model the credit-wallet version of this math with the ElevenLabs pricing calculator.

Companies using this

8 in-corpus companies meter characters: the TTS cluster (ElevenLabs, LMNT, PlayHT, Hume AI, Speechmatics, plus Hedra’s credit-denominated speech), and two text-side cases — Rytr’s character-capped free tier and Unbabel’s per-translation character limits on Widn.ai.

Patterns observed

The defining pattern is the falling-rate ladder: every multi-tier vendor prices the marginal character cheaper as the subscription grows — Hume’s overage drops 3x from Starter to Business, LMNT’s falls 30% from Indie to Premium — so the tier ladder is really a volume-discount curve wearing subscription clothing. The second pattern is that voice cloning travels free with the meter: LMNT includes unlimited clones on every tier including free, and ElevenLabs ships instant cloning from its $6 Starter, because cloning drives character volume rather than competing with it.

A third, quieter pattern: the pure character meter is giving way to credit wallets at the platform end. ElevenLabs denominates everything in credits that map closely to characters; Hedra prices speech, video seconds, and image megapixels through one fungible balance. The character survives as the counting rule inside the wallet even where it disappears from the price card.

Counterexamples & variants

Rytr is the cleanest counterexample: it uses the character meter only to define the free tier’s edge (10,000/month, hard cap), then abolishes it — $9/month buys “unlimited generations” with the meter removed entirely. The bet is that for AI writing, predictability sells better than elasticity, the opposite conclusion from the TTS cluster. Hume AI shows the unit’s boundary inside one product line: batch TTS bills per character, but live voice sessions (EVI) bill per minute — when latency and turn-taking enter, the input text stops being the cost driver and the clock takes over, the same split that defines media-minute pricing. And PlayHT’s arc is the cautionary variant: its “Unlimited” $49 plan undercut its own character meter before Meta acquired the company and withdrew self-serve pricing altogether.

What this means for buyers vs vendors

For buyers

Estimate in characters, not words — English runs ~5–6 characters per word, so a “50,000-word” job is a ~300,000-character job — and ask what the meter counts: whitespace, SSML markup, and regenerations typically all bill. Then shop the allowance, not the rate: the included-character ladders are where the real price differences live, and the falling overage curves mean upgrading one tier is often cheaper than paying overage on the current one (Hume’s $73 Starter overage vs $70 Pro tier above is the canonical case).

For vendors

The character is the most legible meter in audio AI — buyers can count it in a text editor — so protect that legibility: publish the counting rules, keep one rate per tier, and put the volume discount in the ladder rather than in negotiation, the way LMNT does. If you span media types, follow Hedra and keep the character as the speech-side exchange rate inside the credit wallet rather than inventing a new opaque unit; and if part of your product is latency-bound, split the meter explicitly (characters for batch, minutes for live) rather than averaging the two into a number neither workload can forecast. Allowance design follows the standard prepaid-credit mechanics: generous included volume, visible burn-down, and overage that doesn’t punish success.