What is it
Per-word pricing is a billing unit common in translation and localization platforms where the metered object is the word count of content processed.
The unit predates the current AI era by decades: human translators and language-services vendors have priced per word for generations because a document’s word count is the most direct proxy for the effort to translate it. Cloud and then AI-assisted platforms inherited it because buyers in localization already tracked words and procurement already had per-word benchmarks — matching that vocabulary removed friction from the sales conversation.
Per-word billing spans two product contexts that share the unit but not the economics. Translation and localization — Crowdin, Lokalise, Unbabel — meter words (under various labels) because localization managers and language-ops leads expect words on an invoice. AI content and voice — Copy.ai for writing, PlayHT for text-to-speech — metered words or their sub-word equivalent, characters, because creators paste scripts of known length. Across both, the word is the atom that makes cost legible to the buyer.
AI now pressures the rate from both sides: as machine-translation quality rises, the marginal cost of a word collapses, forcing platforms to cut rates, shift the meter to a higher-value dimension, or drop per-word billing entirely.
How it works
Per-word pricing has four structural variants in the corpus. The key distinction inside localization is what the word count measures: standing library (hosted) or translation activity (processed).
| Variant | Mechanic | Example |
|---|---|---|
| Per-word / per-character rate | Each unit processed triggers a charge; bill = units × rate | Human translation agencies; PlayHT API ~$0.15–$0.30 per 1,000 characters |
| Hosted-word capacity | A tier includes standing words kept under management; source words × target languages = meter | Crowdin — 60K Free/Pro, 100K Team, 500K Team+ |
| Processed-word throughput | Annual allowance of words actually translated; heavy use tops up to the next tier | Lokalise — 60K/yr Explorer up to 3M/yr Enterprise |
| Unlimited words in subscription | Words excluded from metering; the subscription covers unlimited generation | Copy.ai Chat — unlimited chat words, $29/mo |
The hosted/processed split changes the bill for identical content. Hosted words count what you keep: adding a target language multiplies the meter even in a month with zero translation, so the model rewards stable, slow-moving libraries. Processed words count what you move: a large corpus translated once a year stays cheap, but frequent small updates burn the annual pool fast.
Unit math: The same 10,000-word product translated once into 6 languages consumes 60,000 units under either meter — but Crowdin charges those 60,000 as standing hosted words the month you add the languages, while Lokalise draws them from the annual processed-word pool only when the translation runs. Same number, opposite trigger.
At the pure per-unit end, rates track service quality — human-verified translation with a quality SLA sits an order of magnitude above raw machine output (see the FAQ for the bands). That collapse toward fractions of a cent is why several vendors here stopped exposing a per-word rate at all and bundle the economics into subscription tiers instead. PlayHT’s consumer plans charged $4 per additional 10,000 characters once the annual allotment ran out.
Companies using this
Five companies in the corpus meter words as a billing unit, spanning translation management (Crowdin, Lokalise, Unbabel), AI content writing (Copy.ai), and text-to-speech (PlayHT). The table spans the full spectrum from fully transparent self-serve rate cards to sales-only enterprise quoting.
Patterns observed
Vendors keep the word but change what it means. The word is so entrenched that platforms retain it even after their cost structure stops mapping to it — they re-base it rather than drop it. Crowdin moved from per-string billing (used from its 2009 launch through at least 2019) to a hosted-words capacity meter, re-pointing the word at library size. Lokalise, in its 2025 repackaging, moved from hosted keys and seat limits to processed words, re-pointing it at annual throughput. Same familiar unit on the invoice; a different thing being counted underneath.
The word is a good meter only when input length predicts cost. That is why PlayHT metered the text going in — creators paste scripts of known length — rather than the audio coming out. The choice held for consumer content but became a liability as the product moved toward voice agents, where identical character counts produce widely different speech lengths. The meter that matches the buyer’s mental model can still be the wrong meter for the cost being incurred.
Counterexamples & variants
Unbabel drops the per-word rate at the enterprise level. Its core LangOps platform publishes no per-word figure — the /pricing URL 404s and the only buying surface is a sales-contact form — because blended AI-plus-human translation makes cost per word swing with the quality SLA, language pair, and content type, so a single headline rate would misrepresent it. Its self-serve sibling Widn.ai instead publishes flat monthly tiers (Free, $19/mo, $90/mo, Custom): even a vendor whose obvious value metric is the word reaches for a subscription the moment it sells self-serve.
Lokalise’s processed-words meter penalizes velocity. It rewards large-but-infrequent corpora — a 5M-word product translated once a year fits an annual allowance — but punishes agile teams shipping small frequent updates across many languages. The Growth plan ($375/mo) includes from 225K processed words/year; a 12-language, 3,000-word update run (36,000 processed words each) drains that in roughly six cycles, pushing high-velocity teams onto the Advanced tier ($999/mo) for capacity, not features. An allowance sized for project-based translation is a structural mismatch for continuous, small-batch localization.
What this means for buyers vs vendors
For buyers
Pin down which word the vendor counts before you compare rates — source, hosted, or processed imply different bills for identical content. Then probe whether the count includes whitespace, markup, and regenerations, all of which inflate the meter past the visible document length. If the vendor runs both AI and human-review tiers, benchmark them separately: the word count is the same, but a human-reviewed word can cost an order of magnitude more than a machine-translated one. For a framework on evaluating usage meters, see choosing the right usage metric.
For vendors
Per-word pricing is a credibility signal in localization — buyers expect it and it shortens procurement — but as marginal word-processing cost approaches zero, a per-word rate either becomes too low to capture value or stays anchored to human-equivalent rates your cost structure no longer justifies. The strongest evolution in the corpus carves a separate premium Pro AI word pool alongside the base meter, keeping the vocabulary buyers understand while introducing a value-aligned dimension. The sharper lesson: if the word is your cost driver but workflow automation is your value driver, price the workflow, not the word. See introduction to usage-based pricing for value-metric selection from first principles, and model metering approaches with the usage-based pricing calculator.
| Company | Product | Pricing model | Billing units | Free tier | Verified |
|---|---|---|---|---|---|
| Copy.ai | GTM AI workflow platform | No | 2026-06-15 | ||
| Crowdin | Crowdin (localization management) + Crowdin Enterprise | Yes | 2026-07-23 | ||
| Lokalise | Lokalise localization management platform | No | 2026-06-30 | ||
| PlayHT | Text-to-speech & voice cloning API (PlayAI) | Yes | 2026-06-09 | ||
| Unbabel | AI + human (LangOps) translation platform; Widn.ai self-serve AI translation | Yes | 2026-06-08 |
Explore this theme in the knowledge graph
FAQ
What is per-word pricing?
Per-word pricing is a billing unit where customers are charged based on the number of words in the content processed — typically translated or generated. It is the standard meter in the translation and localization industry, carried over from human freelance rates into AI-assisted platforms.
How much does per-word translation pricing typically cost?
Rates vary enormously by service tier. Human-verified translation with a quality SLA runs $0.05–$0.20 per word. AI-assisted translation (with human review) is typically $0.01–$0.05 per word. Pure AI content generation tools can charge fractions of a cent per word, or include unlimited words in a subscription.
Do AI translation tools still charge per word?
Some do, but the model is evolving. Crowdin uses a hosted-words capacity meter rather than a per-word charge. Lokalise moved to processed words as an annual throughput allowance. Unbabel does not publish a per-word rate at all. Per-word billing is giving way to bundled-allowance and subscription models as AI lowers marginal cost.
What is the difference between hosted words and processed words?
Hosted words (used by Crowdin) is a capacity meter: the total volume of source content kept under management at any time, calculated as source words multiplied by target languages. Processed words (used by Lokalise) is a throughput meter: the words actually moved through translation activity in a year. Hosted words measure the library; processed words measure the work.
Why did PlayHT price on characters and words rather than audio minutes?
PlayHT metered the text going in (characters and words) rather than the audio coming out because creators paste scripts of known length — so word or character count was more legible to its consumer audience than minutes of output. The tradeoff is that this is a poor meter for voice agents, where the same prompt can produce wildly different speech lengths.
Related billing units
- Credit-Based BillingA billing unit where customers pre-purchase or are allocated a pool of credits that deplete as they use the product, often at variable rates per feature.
- Token-Based PricingA billing unit common in LLM and AI products, where customers are charged per input and output token processed.
- Per-Seat PricingA billing unit where the vendor charges a fixed fee per named user, regardless of how much each user consumes.
- Per-Resolution PricingA billing unit unique to AI customer-support products, where the vendor charges only when an AI agent resolves a customer issue without escalation.
- Bandwidth-Based PricingA billing unit where customers are charged per gigabyte of data transferred out of the platform.
- Per-Function-Invocation PricingA billing unit where customers are charged per serverless function invocation, often combined with a separate compute-time charge.
- CPU-Hour PricingA billing unit where customers are charged for the CPU time their workloads consume, typically measured in vCPU-seconds or vCPU-hours.
- GB-Hour PricingA billing unit where customers are charged for the memory their workloads consume over time, measured in gigabyte-hours.
- GPU-Hour PricingA billing unit where customers are charged for GPU time consumed, typically measured per-second or per-hour by GPU type.
- Per-API-Call PricingA billing unit where customers are charged per API request, regardless of payload size or processing time.
- Per-GB Storage PricingA billing unit where customers are charged per gigabyte of data stored on the platform per month.
- Media-Minute PricingA billing unit where customers are charged per minute of audio or video processed — used by speech, voice, and video AI vendors.
- Per-Request PricingA billing unit where customers are charged per request served — the generic meter for inference endpoints, search, scraping, and browser infrastructure.
- Per-Event PricingA billing unit where customers are charged per event ingested — the native meter of observability and billing-infrastructure platforms.
- Vector Storage PricingA billing unit where customers are charged for vectors stored or indexed — the storage dimension of vector database pricing.
- Per-Character PricingA billing unit where customers are charged per character of text processed — the standard meter for text-to-speech and translation.
- Per-Document PricingA billing unit where customers are charged per document processed or generated — common in AI writing, SEO, and document-intelligence tools.
- Per-Page PricingA billing unit where customers are charged per page crawled, parsed, or rendered — the meter for web scraping and document parsing.
- Per-Transaction PricingA billing unit where customers are charged per financial or billing transaction processed — the meter of billing and accounting platforms.
- Active-User PricingA billing unit where customers are charged per monthly or daily active user rather than per provisioned seat.
- Per-Task PricingA billing unit where customers are charged per task an automation or agent executes — Zapier's historical unit, now spreading to AI agents.
- Per-Unit PricingA billing unit used by robotics, hardware AI, and some SaaS companies where the metered object is a physical or abstract 'unit' — a robot deployed, a device sold, or a defined deliverable.
- Workflow Execution PricingA billing unit where each end-to-end workflow or automation run is metered and billed, regardless of the compute steps it contains.
- Per-Message PricingA billing unit where each individual message or reply in a conversation is metered, common in AI chat and voice platforms.
- Per-Invoice PricingA billing unit used by billing infrastructure platforms where each invoice generated or processed is metered as the primary cost driver.
- Per-Action PricingA billing unit where each discrete action taken by an AI agent or automation is metered — common in browser automation and agentic workflow tools.
- Per-Image PricingA billing unit where each AI-generated image is metered, common in image generation APIs and multimodal AI platforms.
- Per-Conversation PricingA billing unit where each complete customer conversation — from first message to resolution — is metered as a single chargeable event.
- Per-Record PricingA billing unit where each data record processed, labeled, or extracted is metered — common in data platforms and web scraping services.
- Per-Video PricingA billing unit where each AI-generated video is metered, common in video generation and synthetic media platforms.
- Milestone-Based PricingA billing unit used in drug discovery and biotech AI where payment is tied to achieving defined research milestones rather than time or compute consumed.
- Per-Outcome PricingA billing unit where payment is triggered by verified outcomes delivered — distinct from outcome-based pricing models, this refers specifically to 'outcomes' as a countable billing unit.
- Per-Datapoint PricingA billing unit where each individual data measurement or signal ingested is metered — common in cloud cost intelligence and ML evaluation platforms.
- Per-Interaction PricingA billing unit where each patient-agent or user-agent interaction is metered, common in healthcare AI and customer engagement platforms.
- Data Licensing PricingA pricing structure where access to proprietary datasets or data assets is licensed separately from the software or services, common in AI training data and clinical data platforms.
- Robot-Hour PricingA billing unit where each hour a robot or autonomous system operates is metered — the robotics equivalent of a GPU-hour.
- Per-Contact PricingA billing unit where each contact or lead in the database is metered, common in AI sales development and outbound automation platforms.
- Per-Mailbox PricingA billing unit where each connected email mailbox or sending account is metered, common in AI outbound sales and email automation platforms.
- Browser-Hour PricingA billing unit where each hour of headless browser compute time is metered, common in web scraping and browser automation platforms.
- Per-Generation PricingA billing unit where each AI-generated creative asset — image, video, or design — is counted as a 'generation' and metered accordingly.
- Per-Ticket PricingA billing unit where each customer support ticket handled by an AI agent is metered — common in AI customer service platforms.
- Per-Log PricingA billing unit where each LLM request log ingested or stored is metered — common in AI observability and evaluation platforms.
- Per-Trace PricingA billing unit where each distributed trace — a complete record of an LLM request chain — is metered, common in AI observability platforms.
- Per-IP PricingA billing unit where each IP address or proxy endpoint allocated is metered — used by web scraping proxy providers.
- Per-Device PricingA billing unit where each hardware device or endpoint connected to the AI platform is metered.
- Per-Case PricingA billing unit used in legal AI platforms where each case or matter processed by the AI is metered.
- Per-Report PricingA billing unit where each AI-generated report or analysis document is metered as a discrete output.