UD5 Toolkit
Text to Anki CSV - Online Flashcard Converter
Format a list of Q&A pairs and export as a CSV ready for Anki import. Simple line‑based template. Local.
i18n JSON to CSV Converter - Online Flatten Translation Files
i18n JSON ↔ CSV Converter
Flatten nested translation files, merge multilingual JSONs, and convert between formats seamlessly
JSON → CSV
CSV → JSON
JSON Input
Drop JSON files here or click to browse
Single file: key-value CSV | Multiple files: merged multilingual CSV
Options
Frequently Asked Questions
What is i18n JSON flattening?
Flattening converts nested JSON structures like {"common":{"save":"Save"}} into flat key-value pairs like common.save,Save. This makes translation files easier to manage in spreadsheets and share with non-technical translators.
Why convert JSON translations to CSV?
CSV files can be opened in Excel, Google Sheets, and other spreadsheet tools. This allows translators, product managers, and non-developers to easily review, edit, and manage translations without touching raw JSON.
How does multilingual file merging work?
Upload multiple JSON files (e.g., en.json, zh.json, es.json) simultaneously. The tool extracts language codes from filenames, flattens each file, and merges them into a single CSV with columns: key, en, zh, es, etc. Missing keys are left blank.
What separator should I use for keys?
The dot (.) separator is most common and works with frameworks like i18next. Choose the separator that matches your i18n library's convention. Underscores and slashes are also popular. If unsure, dot is the safest default.
Can I convert CSV back to nested JSON?
Yes! Switch to the CSV → JSON tab. The tool uses the key separator to reconstruct the original nested structure. For multilingual CSVs, you can export each language column as a separate nested JSON file — perfect for syncing back to your codebase.
Is UTF-8 BOM important for CSV?
Yes, especially for translations with non-Latin characters (Chinese, Arabic, Cyrillic, etc.). UTF-8 with BOM ensures Microsoft Excel correctly detects the encoding. Without BOM, Excel may display garbled text. Our default setting includes BOM for maximum compatibility.
Which i18n frameworks use nested JSON?
Popular frameworks like i18next, react-intl (with nested namespaces), vue-i18n, ngx-translate (Angular), and Laravel localization all support or use nested JSON structures. This tool works with any framework that uses flat or nested JSON translation files.
How are arrays and special values handled?
When flattening, arrays and complex objects at leaf nodes are serialized using JSON.stringify() so they're preserved in the CSV. When converting back with "Smart type detection" enabled, the tool attempts to restore booleans, numbers, and null values automatically.
FormData to JSON Converter - Online Debug Multipart
Fill in a form and see the FormData object as JSON. Perfect for debugging multipart form submissions. Client-side.
Pseudo‑Localization Generator - Online Test UI for i18n
Transform English text into pseudolocalized text with accents, expansion, and brackets. Test your UI's readiness for translation.
JavaScript Object Diff Viewer - Online Compare Data
Paste two JSON objects and see a highlighted diff showing what was added, removed, or changed. For API testing.
Large CSV File Splitter - Online Break into Chunks
Split a large CSV into smaller files by row count. Preview each chunk. No upload; streamed locally.
CSV to Excel Converter - Online Save as XLSX
Convert CSV data to a real Excel spreadsheet with multiple sheets and simple formatting. Fully local.
JSON to Excel (.xlsx) Converter - Online Spreadsheet Creator
Paste a JSON array of objects and download a properly formatted .xlsx Excel file. No server; uses SheetJS in the browser.
Text to Anki Flashcards - Online CSV Generator
Write Q&A in a simple format and export as a CSV file compatible with Anki. Perfect for rapid card creation. Local.
Accept‑Language Header Visualizer - Online Locale Match
Paste your Accept‑Language header and see which languages your site should serve based on quality values. Internationalization helper.
CSV to YAML Converter - Online Config File Generator
Paste CSV data and transform it into a well‑structured YAML array of objects. Choose key mapping. Perfect for devOps and data migration.
ICS to JSON Converter - Online Calendar Data Export
Parse an iCalendar file and output the events as a clean JSON array. For developers integrating calendar data. Client‑side only.
CSV to iCalendar (ICS) Converter - Online Calendar Events
Map CSV columns to event fields and generate a valid .ics file. Import into Google Calendar, Outlook, or Apple Calendar. Local.
JSON List to CSV - Online Flat Array Converter
Convert a JSON array of strings or numbers into a single‑column CSV. Quick data dump. Local.
JSON to Graph Visualization - Online Tree Diagram
Paste a JSON object and see a dynamic, draggable tree graph representation. Excellent for debugging nested data.
JSON to TypeScript Interface - Online Type Gen
Paste a JSON object and instantly get a TypeScript interface definition. Handles nested objects and arrays. Local only.
SQL INSERT from CSV - Online Data to Statement
Paste CSV and get a list of SQL INSERT statements. Define table name and column mapping. All local conversion.
CSV Column Filter - Online Keep or Remove Columns
Paste CSV data and pick which columns to keep or drop. Rearrange column order by dragging. Download the new file. All local.
SQL INSERT to CSV Converter - Online Data Export
Paste SQL INSERT statements and extract the data into a clean CSV table. Works with multiple rows. Local parser.
Text to Character Array - Online For Programmers
Split a text into an array of individual characters, ready to paste into code. Options for quotes and newlines.
CSV to HTML Table - Online Generate Responsive Code
Paste CSV and get a beautiful HTML table with sortable headers (optional). Copy the full HTML/CSS snippet. Local.
CSV to Wiki Table Converter - Online MediaWiki Markup
Paste CSV data and instantly get a formatted MediaWiki table code. Ideal for Wikipedia editors and internal wikis.
JSON to Go Struct / TypeScript / JSON Schema - Online
Paste a JSON object and quickly generate typed structs for Go, TypeScript interfaces, or a JSON Schema. Perfect for API integration.
CLI Table Generator - Online JSON to Console Log Style
Paste a JSON array and view it as a formatted console.table() style output. Copy for terminal apps. Local.
JSON to SQL INSERT/UPDATE Converter - Online
Parse a JSON array and generate SQL INSERT or UPDATE statements. Perfect for data migration. Client‑side only.
JSON Diff Compare - Online Highlight Differences
Paste two JSON objects and find the structural differences with side‑by‑side highlighted output. Indispensable for API debugging.
JSON to JSON Schema Generator - Online Infer Structure
Paste a sample JSON object and generate a basic JSON Schema describing its types and required fields. Local inference.
Random JSON Generator - Online Create Sample API Responses
Generate random JSON data with customizable fields (users, products, orders). Useful for frontend mocking. All local.
Lottie Animation Previewer - Online JSON Player
Paste Lottie JSON code or upload a .json file and see the animation play. Control speed and loop. Perfect for developers.
CSV Viewer & Editor - Online Spreadsheet Tool
View and edit CSV data in a familiar table interface. Add/delete rows and columns, sort, and export. Fully local, no cloud sync.
JSON to XML Converter - Online Data Interchange Tool
Seamlessly convert JSON objects into valid XML documents. Control root element naming and attribute formatting. Entirely local, keeping your data safe.