--- title: Free JSON Translator: Translate JSON Files Online description: Translate JSON files online free - string values are translated while keys and placeholders stay untouched. 15-day free trial, no card. Try Smartcat free. canonical: https://www.smartcat.com/software-translator/translate-json-free/ language: en updated: 2026-08-24 --- # Free JSON Translator: Translate JSON Files Online ## Translate a JSON File Online Free — Structure Stays Intact Drop in a .json file and get back JSON in any of 280+ languages: string values translated, keys and nesting untouched, and your placeholder tokens locked as tags. - [Book a demo](https://www.smartcat.com/book-a-demo/?n-upl) - [Sign up free](https://smartcat.com/sign-up?n-upl) ## Is Translating a JSON File Online Really Free? Yes — you can translate a JSON file online free with Smartcat. Free means 15 days with 15,000 Smartwords and no credit card, with full access to translation capabilities (the API is paid-only). Upload your file, pick languages, and download JSON with every key where it was. ### 15 days ### free, no credit card Smartcat does not have a free-forever plan; it has a free 15-day trial with no credit card required. You enter payment details only if you subscribe afterwards. ### 15,000 ### Smartwords included Translation is metered in Smartwords, at one Smartword per source word. The trial allowance covers a single file or a batch comfortably. ### 280+ ### target languages Pick one source and as many targets as you need in one project, and download one output file per language. ### What the free trial covers JSON file translation into 280+ languages, multi-file upload, the translation editor, translation memory and glossaries, and a trial allowance of 15,000 Smartwords — full access to translation capabilities for 15 days, with no credit card. ### How translation is metered Translation is metered in Smartwords, at one Smartword per source word. When the trial ends, translation stops until you pick a paid plan. There is no free-forever plan. ### What the trial does not include The API. API access is a paid feature of the Anticipate and Autonomous plans, it requires a company account rather than a freelancer one, and it is not switched on for trial accounts. ### Keys are never translated Only the string values change. Keys, numbers, booleans and nesting come back exactly as they went in. ### Nested objects keep their shape Nested object structures are preserved, and plurals can be kept as ICU MessageFormat. For the element-by-element breakdown, including the plural caveats, see [what survives translation](https://www.smartcat.com/json-translator/) on the JSON translator page. ### Placeholders are locked as tags Placeholder tokens are imported as non-editable tags. Smartcat matches them with regular expressions you set once on the Placeholders tab in Settings, so the pattern your codebase uses is the pattern that gets protected. ## How Do You Translate a JSON File Online for Free? ### Upload the file Drag your .json into the box above. No account gymnastics: the trial starts when you sign up, and no card is required. ### Pick your languages One source, one or many targets, from 280+. ### Let the AI translate String values are translated; keys, nesting and placeholder tags are left where they were. ### Check anything you want to fix Open the editor to read the strings side by side. Short UI strings are the ones worth a human glance before you ship. ### Download the translated file Same keys, same nesting, new language — one output file per target language. ### Decide whether you need a plan One file, or one batch, and the job ends there? The trial covers it. Localizing on every release, as a team? That is a different job — see the [JSON localization workflow for teams](https://www.smartcat.com/json-translator/). ### Application UI ### User Interface Localization Translate JSON files used in apps to localize buttons, messages, and menus across different languages while keeping character limits in mind. ![Application UI](https://gqucouwbfxremfdhdosu.supabase.co/storage/v1/object/public/sc-store/17540510780251.webp) - [Start UI Translation](https://www.smartcat.com/software-localization/) ### API & Docs ### Technical Content Translation Translate API responses, documentation, and structured content while maintaining clarity and accuracy for developers. ![API and Docs](https://gqucouwbfxremfdhdosu.supabase.co/storage/v1/object/public/sc-store/17540510834932.webp) - [Localize Documentation](https://www.smartcat.com/technical-translation/) ### Web Content ### Website Content Localization Translate your website's content, often stored in JSON-like schema. Improve your search engine optimization (SEO) and user experience globally. ![Web Content](https://gqucouwbfxremfdhdosu.supabase.co/storage/v1/object/public/sc-store/17540510871043.webp) - [See Website Translator](https://www.smartcat.com/website-translator/) ### Game & App ### Game and App Content Translation Translate in-game text, app content, and UI elements easily with Smartcat's JSON translator. Perfect for teams working across multiple languages. ![Game and App Content](https://gqucouwbfxremfdhdosu.supabase.co/storage/v1/object/public/sc-store/17540510954564.webp) - [Explore App Translation](https://www.smartcat.com/multimedia-translation/) ### For development teams Wire JSON localization into your CI/CD pipeline with the Smartcat API — a paid feature of the Anticipate and Autonomous plans that needs a company account, and one that is not switched on during the free trial. Stop spending development hours on manual file handling. Developer Solutions ### For product managers Launch features globally from day one. Our platform enables simultaneous translation across all target languages, eliminating regional release delays. Product Localization ### For L&D and marketing teams Manage multilingual content at scale. Create and maintain training or marketing that stays in sync with product updates across all languages. L&D Translation ## More than just a free JSON translator ### 9.6/10 for ease of setup on G2 ### 9.3/10 for ease of use on G2 ### 1,000+ enterprise brands ### SOC 2 Type II compliant Ready to Localize Your JSON Files? Free for 15 days with 15,000 Smartwords, no credit card. There is no free-forever plan: after 15 days you pick a paid plan or stop. - [Book a personalized demo](https://www.smartcat.com/book-a-demo/) - [Try Smartcat Free](https://smartcat.com/sign-up?) Smartcat’s supplier management feature alone has saved us about 1,000 hours of yearly administrative and project management time (equivalent to 1/2 of an FTE)… Peggy Liao Language Access Program and Policy Specialist, City of Seattle - [Read Case Study](https://www.smartcat.com/cases/city-of-seattle/) We've been able to increase our productivity by 50% while reducing our outsourcing costs by 50%. This has had a huge impact on our bottom line. Julia Emge Director of Content Creation, expondo - [Read Case Study](https://www.smartcat.com/cases/expondo/) What really won us over was how easily Smartcat integrated with our existing tools. Not having to manually export and import files is a massive time-saver. Julia Emge Director of Content Creation, expondo - [Read Case Study](https://www.smartcat.com/cases/expondo/) ## How global teams succeed with Smartcat ### 50% ### increase in productivity expondo increased productivity by 50% while reducing outsourcing costs by 50%, localizing in-house across 18 countries. - [Read case study](https://www.smartcat.com/cases/expondo/) ### 1,000 hours ### admin time saved yearly The City of Seattle saved about 1,000 hours of yearly administrative and project-management time by automating paperwork and payment for the 50+ community reviewers it works with, and cut translation expenses by 17%. - [Read case study](https://www.smartcat.com/cases/city-of-seattle/) ### 31 hours ### of work time saved monthly Babbel's marketing and L&D teams save 31 hours of work every month. Time they can now use for more strategic tasks. - [Read case study](https://www.smartcat.com/cases/babbel/) ## Secure and compliant JSON translation Same infrastructure as paid: Smartcat is SOC 2 Type II compliant, files are encrypted in transit and at rest, and workspaces are isolated. Trial accounts are not a lower security tier. Details on the [security page](https://www.smartcat.com/security/). ## One File or a Whole Batch — Free for the Next 15 Days Upload your JSON, download it back in a new language with its keys and nesting where you left them. No credit card, no surprise paywall mid-file. - [Get Started](https://smartcat.com/sign-up?from_trusted-software-translation) ## Frequently Asked Questions ### Is it really free? For 15 days, yes — 15,000 Smartwords, no credit card, with full access to translation capabilities (the API is not included). There is no free-forever plan; after the trial you choose a paid plan or stop. ### Do I need a credit card to start? No. You enter payment details only if you subscribe after the trial. ### How large can the file be, and how many can I upload? The documented ceiling is **global rather than JSON-specific**: **6 GB** per document or project file, and the guidance is to split anything over **1 GB** into smaller parts so it processes faster. On file count there is **no cap at all** — batch uploads of hundreds of files are supported, and that does not change between the trial and any paid plan. Plans differ on integrations and Marketplace billing, not upload limits. ### Can I translate one JSON file into several languages at once? Yes — pick multiple target languages in one project and download one output file per language, all generated from the same source. ### What stays intact in the translated file? Keys are never translated. Placeholder tokens are locked as non-editable tags — Smartcat matches them with regular expressions you set once on the Placeholders tab in Settings, so the pattern your codebase uses is the pattern that gets protected. Nested objects keep their shape, and plurals can be kept as ICU MessageFormat. For the element-by-element breakdown, see the [JSON translator page](https://www.smartcat.com/json-translator/). ### Where does this fall short? Two honest things. - **Short UI strings are the weak spot** — machine translation cannot tell whether "Save" is a button or a discount, so give one-to-three-word strings a human glance in the editor before shipping. - **Free ends on day 15.** If you only ever need one file translated once and do not care about translation memory, glossaries, or where the file is processed, this is more tool than you need. What you get here for the same zero dollars is a real editor, structure safety, and a security posture you can show your team. ### When should I upgrade to a paid plan? Stay on the **free trial** if you have one file, or one batch, and the job ends there — the trial is genuinely enough for that. A **paid plan** starts paying for itself when: - You **re-translate on every release** — translation memory means changed strings are the only new linguistic work, though re-uploading a file still consumes Smartwords. - **Multiple people** touch the locale files. - You want **terminology enforced** across products. Pricing is on the [pricing page](https://www.smartcat.com/pricing/) — no call required to see it.