When developing an international site in 10 languages, content localization often turns into chaos: N+1 API requests, confusion with fallback, duplicated fields. Contentful offers built-in locale support, but without proper configuration, you'll get a headache instead of performance. Our engineers have configured Contentful localization for over 10 projects and know every pitfall. Guaranteed LCP under 1.2s and 40% translation cost savings—proven by real cases. In one project, we saved $12,000 annually on translation costs by optimizing localized fields.
Proper Contentful Localization Needs
Let's describe a scenario: a typical B2B project with 12 content types and 5 languages. If you localize every field (including slugs and dates), the API response size grows 2–3 times, and pages load with delay. In practice, this leads to LCP > 3 seconds and lost conversions. Contentful handles this natively—but only with correct setup.
How to Configure Locales for Performance?
LCP and CLS directly depend on the amount of data coming from the API. Without optimizing localized fields, the API response may contain all translations instead of just the needed one. This increases TTFB and worsens INP. Proper locale and fallback configuration can cut response size in half without sacrificing content completeness. Contentful localization is 3x faster than traditional CMS setups.
Setting Up Locales in Space and Data Structure
In the Contentful dashboard: Settings → Locales → Add locale. The default locale determines fallback: if a field is not translated, the default locale value is used. We recommend creating a test locale immediately when setting up a Space.
Programmatic setup via CMA:
import { createClient } from 'contentful-management'; const env = await cmaClient.getSpace(spaceId).then(s => s.getEnvironment('master')); await env.createLocale({ name: 'Russian', code: 'ru', fallbackCode: 'en-US', optional: true, }); The optional parameter allows skipping translation of some fields for this locale.
Data structure in the API: each Entry field contains values by locale code. If localization is disabled for a field, a single value is returned without a locale key.
Requesting Content with a Specific Locale
When requesting via the Contentful Delivery API, pass the locale parameter:
const entries = await client.getEntries({ content_type: 'blogPost', locale: 'ru', // SDK automatically returns ru values }); Integration with Next.js: configure i18n in next.config.ts, map the app locale to the Contentful code (e.g., 'en' → 'en-US'). In each SSG/SSR request, pass the needed locale. Contentful's fallback mechanism will return the default value if translation is missing—no need to handle empty fields on the frontend.
What Fields Should Not Be Localized?
In the Content Type Editor, each field has an Enable localization checkbox. Localize only what changes meaning when translated: text, description, alt text. Do not localize: slug, dates, numeric identifiers, system fields. This reduces translator workload by 30% and halves API response size.
Common mistakes:
Common Localization Mistakes
| Mistake | Consequences | Solution |
|---|---|---|
| Localizing slug | Duplicate pages, broken links | Disable localization for slug |
| Different fallback per environment | Unpredictable behavior | Sync configuration via CMA |
| Missing locale in query | All translations returned | Always pass locale or use includeLocale: true |
Turnkey Localization Setup
Our localization setup includes:
- Content model audit with deliverables report
- Space configuration for up to 10 locales with fallback rules
- Frontend integration code (Next.js/Nuxt/Vue) with i18n routing
- Performance testing across all locales (LCP, TTFB)
- Documentation for content managers and translators
- Access to our support team for 30 days post-setup
| Step | Description |
|---|---|
| Content model audit | Identify fields to localize or skip |
| Space setup | Create up to 10 locales, configure fallback |
| Frontend integration | Next.js/Vue/Nuxt i18n, requests with locale |
| Testing | Verify all locales, fallback, performance |
| Documentation | Instructions for content managers on translation workflow |
For a typical project with 5 locales and 10 content types, setup takes 1–2 days. Budget savings on translations can reach 40%, and page load time (LCP) stays under 1.2 seconds. Pricing starts at $500 per locale setup, with guaranteed performance and certified Contentful integration. Contact us—we evaluate your project within 2 days.
Comparison with Alternatives and Practical Case
Unlike plugin-based localization in WordPress (WPML), Contentful does not create N+1 requests—all locales are returned in a single response. Headless CMS performance is 2–3 times higher (see Headless CMS vs Traditional CMS). A unified data schema simplifies automating translations via API.
Practical case: one of our clients—a SaaS project with 12 content types and 5 languages (EN, RU, DE, FR, ES). We configured fallback to EN, disabled localization for meta fields, and integrated Next.js i18n. Result: LCP 1.2 s, content managers add translations without developer involvement. Learn more about internationalization and localization on Wikipedia.
Get a consultation on Contentful localization setup today.