Is app localization worth the cost?
It’s the question every product leader asks before committing budget. The upfront investment is real: translation, tooling, ongoing maintenance. The payoff feels uncertain.
This article provides a framework for answering that question with data.
Understanding the True Cost of Localization
Before calculating ROI, you need an honest view of costs. Localization isn’t just translation, it’s an ongoing operational capability.
Cost Components
| Category | One-Time Costs | Ongoing Costs |
|---|---|---|
| Translation | Initial full translation | New features, updates |
| Tooling | TMS setup, integration | Subscription, maintenance |
| Engineering | i18n architecture, extraction | Sync automation, QA |
| QA | Initial linguistic testing | Regression testing per release |
| Design | UI adaptation, layout fixes | Ongoing layout issues |
The Scaling Curve
Many teams budget for the first language but not the compounding complexity:
Language 1: Everything is new. You build infrastructure, train the team, establish processes. High cost, but foundational.
Languages 2-5: Marginal cost decreases. Infrastructure exists. Each language adds less overhead than the last.
Languages 6+: Complexity returns. More edge cases. More testing permutations. More support channels. Coordination overhead grows.
Budget accordingly. Language 10 does not cost the same as language 3.
The Cost of Poor Quality
One cost that rarely makes the spreadsheet: brand damage from inconsistent quality.
Professional translation for top 3 languages and machine translation for the rest means French users love you while Polish users think your app is sketchy. The direct cost is lower. The indirect cost (lost trust, negative reviews, reduced conversion in “secondary” markets) often exceeds the savings.
Warning signs:
- App store ratings differ significantly by country
- Support tickets mention “bad translation” or “confusing text”
- Conversion rates vary wildly between comparable markets
Measuring Localization Impact
The biggest challenge in localization ROI is measurement. Most analytics aren’t set up to answer “did localization increase revenue?”
Typical dashboards show global numbers: total revenue, total users, overall conversion. They don’t answer:
- How much revenue comes from German-speaking users specifically?
- Did conversion improve in Japan after localization?
- What’s the lifetime value difference between English and Spanish users?
Metrics to Track by Locale
| Metric | What It Tells You |
|---|---|
| Conversion rate | Does localized UX improve purchase/signup? |
| Bounce rate | Are users leaving because of language barriers? |
| Time to value | Do localized users activate faster? |
| Support ticket volume | Does localization reduce confusion-based tickets? |
| Retention (D7, D30) | Do localized users stick around longer? |
| Revenue per user | Do localized users spend more over time? |
What the Research Shows
The European Commission’s 2011 Eurobarometer survey of 13,752 internet users across EU member states found:
| Finding | Percentage |
|---|---|
| Prefer websites in their own language | 90% |
| Never buy from websites in other languages | 42% |
| Feel they miss information due to language barriers | 44% |
| Will purchase in a foreign language | 18% |
A 2024 follow-up shows English proficiency has grown (especially in Spain, Portugal, and Eastern Europe), but native language preference remains dominant. Younger users (15-24) are more multilingual, which raises expectations for what “properly localized” means.
The specific conversion lift varies by market and product. However, when 42% of users refuse to purchase in a foreign language, the ceiling on non-localized conversion is clear.
How to Prioritize Languages
You can’t localize everything at once. Prioritization maximizes ROI.
High-signal approach: Start with markets where you already have traction without localization. These users want your product badly enough to struggle through English. Removing that friction converts latent demand.
Score each potential market on:
| Factor | Why It Matters |
|---|---|
| Existing demand | Current traffic/signups from region indicates proven interest |
| Market size | TAM for your product category sets the ceiling |
| Competition | Localized competitors mean you’re losing to friction |
| Localization complexity | RTL, CJK, or complex plural rules affect cost |
When to Start
Too early: Localization before product-market fit wastes resources. If core features still change monthly, you’ll retranslate constantly.
Signs you’re ready:
- Stable product with consistent messaging
- Measurable traffic/signups from target markets
- Customer requests for specific languages
- Competitor activity in target markets
- Resources to maintain translations ongoing
Too late: If competitors have established localized presence in markets where you have demand, every month of delay is lost market share.
Building the Business Case
A localization business case needs four components:
1. Current State Document international traffic, conversion gaps vs. English markets, and customer feedback about language barriers.
2. Opportunity Size Calculate addressable market in target locales. Apply conservative conversion assumptions based on Eurobarometer data (e.g., if 42% won’t buy in a foreign language, that’s your minimum addressable lift).
3. Investment Required Separate one-time costs (initial translation, tooling, engineering) from ongoing costs (new content, maintenance, QA). Be explicit about the 6+ language complexity increase.
4. Pilot Proposal Propose a single-market pilot. Measure results. Use data to justify expansion. This de-risks the decision while building internal capability.
Localization has real costs. But so does not localizing: lost revenue, competitive disadvantage, and missed market opportunities.
For most growing products with international demand, the math works. The question is when and how to invest. Start with data, prioritize based on existing traction, and build infrastructure that scales beyond the first language.
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