JSON to CSV

Convert JSON arrays/objects into csv format.

JSON to CSV — What's New in Version 3.1.0 This is the largest update this extension has ever received. Every part of the converter has been rebuilt: a security hole has been closed, long-standing data-corruption bugs are fixed, the tool now handles the nested JSON that real APIs actually return, and it works in 43 languages instead of just a handful. It is also ten times smaller to install, and it still asks for zero permissions. A SECURITY FIX YOU SHOULD KNOW ABOUT Previous versions inserted the converted result into the page as markup, so JSON containing certain characters could break out of the output box and inject content into the extension's own page. It also silently corrupted innocent data: any value containing an HTML-like fragment could truncate your CSV without warning. The output panel is now built safely, so converted text is always treated as text, never as code. If you convert data from a source you do not fully control, this fix alone is worth the update. YOUR ACCENTS AND SPECIAL CHARACTERS NOW SURVIVE EXCEL The most common complaint about the old version was that names like "Zoé" or "Köln" arrived in Excel as garbled nonsense, because files were saved without a byte-order mark and with the wrong file type. Both are fixed. Save a CSV, double-click it in Excel on Windows, and your characters appear exactly as they were. If you prefer the old behaviour, the byte-order mark is a checkbox you can switch off. NESTED JSON FINALLY BECOMES COLUMNS Real-world JSON is rarely flat. Previously, an object like {"user":{"name":"Bo"}} produced a single column containing an unreadable blob of raw JSON. Now it produces a proper "user.name" column. Arrays can be expanded too: flattened into numbered columns, or unwound so each element becomes its own row. The extension now handles the output of an actual API, not just pre-flattened data. A REAL OPTIONS PANEL You are no longer stuck with one fixed output format. You can now choose your delimiter — comma, semicolon, tab, or pipe. The semicolon option matters enormously if you use Excel in Germany, France, Spain, the Netherlands, or any other region where the comma is a decimal separator; previously those users had to fix every file by hand. You can also choose LF or CRLF line endings, turn the header row on or off, and control every flattening behaviour described above. Your settings are remembered between sessions. CONVERT CSV BACK TO JSON The extension now works in both directions. Paste or upload a CSV and get clean JSON back, with numbers, booleans, and empty values correctly detected rather than left as strings. Quoted values stay as text, so an ID like "007" does not silently become the number 7, and very large numbers keep their precision instead of being mangled. Dotted column names such as "user.name" are rebuilt into properly nested objects, so a round trip from JSON to CSV and back returns what you started with. SEE YOUR DATA BEFORE YOU SAVE IT A new table view shows your converted output as actual rows and columns, so you can confirm the delimiter and flattening are right before downloading anything. The raw text view is still there, one click away. FASTER, SMOOTHER, AND IT NO LONGER FREEZES Large documents used to lock up the whole tab with no sign anything was happening. Conversion now runs in the background with a progress indicator, so the page stays responsive. Drag a file straight onto the page instead of hunting through a file picker, and conversion starts automatically after an upload or paste. Downloads take their name from your source file, so orders.json becomes orders.csv. Copying to the clipboard is reliable and confirms when it worked. Dropping a .csv switches to reverse mode automatically. BETTER ERROR MESSAGES Invalid JSON no longer shows a cryptic internal message. The extension tells you the exact line and column of the problem and moves your cursor there. TEN TIMES SMALLER, STILL ZERO PERMISSIONS Old versions shipped roughly four megabytes of unused libraries, fonts, and developer files to every user. All of it is gone, so the extension installs in a fraction of the space and loads faster. It still requests no permissions whatsoever: every conversion happens locally, and your data never leaves your computer. FULLY TRANSLATED, INCLUDING RIGHT-TO-LEFT The interface is now completely translated into all 43 supported languages rather than falling back to English for most of the screen. Arabic, Persian, and Hebrew now display in proper right-to-left layout for the first time. FIXED ALONG THE WAY The file encoding selector now applies immediately, instead of ignoring you until you re-picked the file; three options that never worked are gone and a mislabelled one is corrected. Text in the input and output boxes can be selected normally again. The "new" badge no longer reappears after every update. A dark theme follows your system setting, with a manual toggle.