Tablizer

Convert JSON Lines to BBCode Online

Paste a JSON Lines table below, edit it if you need to, and get BBCode back. The conversion runs in your browser, so nothing is uploaded, there is no size limit and there is no signup.

From

The only part of this site that uses a server. The address is sent to it so the page can be fetched, because a browser is not allowed to fetch someone else's page itself. Your own files are never involved.

Nothing here is uploaded. The parsing happens on this page.
Edit
Paste or upload something above and it will appear here.
ToDataMarkupDocumentsCodeSchemasImages

The output will appear here once there is a table to convert.

What JSON Lines is

JSON Lines is one complete JSON object per line, with no enclosing array and no commas between records. The file is not valid JSON as a whole, and that is the point.

Log pipelines, machine learning datasets and anything that appends records or reads them in a stream.

What BBCode is

BBCode uses square-bracket tags. Table support is not universal, but table, tr, th and td are widely implemented.

phpBB, vBulletin and forum software descended from them.

What changes when you convert JSON Lines to BBCode

Each line is parsed on its own, so a corrupt record does not take the file with it. Keys are unioned across lines in first-seen order, so a record missing a field leaves that cell empty rather than shifting the columns.

Check that your forum has table tags enabled. Many boards ship with them switched off.

What carries over from JSON Lines to BBCode

JSON Lines records 5 things about a table that BBCode has no way to hold.

JSON Lines distinguishes a number from the text of a number; BBCode does not, so every value arrives as text and has to be re-parsed by whatever reads it next.

An empty cell and a missing one are the same thing in BBCode, so a null and an empty string in the JSON Lines both come out blank and can no longer be told apart.

JSON Lines can hold a value that is itself a list or an object. BBCode has only flat cells, so nested values are flattened into one cell rather than being spread across columns.

The keys stop being repeated: BBCode writes the column names once at the top, so the same table takes noticeably less space.

JSON Lines can be read one record at a time. BBCode has to be complete before it means anything, so the whole table is held in memory while it is written and a file that gets cut off part way through is not partly usable - it is unusable.

BBCode is the end of the line for this data. Reading the table back out of it is a separate and much harder problem than writing it, so keep the JSON Lines if you will need the values again.

The identifier 007 comes out of the BBCode as 007. Reading it as a number would have made it 7, and an id that changes value is worse than one that stays text.

The role "Analyst, data" survives with its comma, in one cell rather than split across two. That is the first thing to check in any converted table, and the usual place a BBCode file goes wrong.

The quotes around Jonah "Jo" Pryce are left as a plain quote character in the BBCode.

A worked example

Three rows of staff data, with an identifier that has a leading zero, a value containing a comma, a value containing quotes and one blank cell. Those are the four places formats disagree, so they are the four places to look.

JSON Lines in
{"id":"007","name":"Halima Yusuf","role":"Analyst, data","started":"2024-03-15","hours":"38.5"}
{"id":"012","name":"Jonah \"Jo\" Pryce","role":"Engineer","started":"2025-11-02","hours":""}
{"id":"104","name":"Wei Chen","role":"Manager","started":"2023-06-30","hours":"40"}
BBCode out
[table]
  [tr][th]id[/th][th]name[/th][th]role[/th][th]started[/th][th]hours[/th][/tr]
  [tr][td]007[/td][td]Halima Yusuf[/td][td]Analyst, data[/td][td]2024-03-15[/td][td]38.5[/td][/tr]
  [tr][td]012[/td][td]Jonah "Jo" Pryce[/td][td]Engineer[/td][td]2025-11-02[/td][td][/td][/tr]
  [tr][td]104[/td][td]Wei Chen[/td][td]Manager[/td][td]2023-06-30[/td][td]40[/td][/tr]
[/table]

Questions

How do I convert JSON Lines to BBCode?

Paste your JSON Lines into the box above or drop the file onto it. Check the table in the grid, then copy or download the BBCode from the output panel. It takes one step and the data never leaves your browser.

What is the difference between JSON and JSON Lines?

JSON wraps records in an array, so a reader must load the whole document before it can use any of it, and appending means rewriting the file. JSON Lines has no wrapper, so records can be streamed and appended one at a time. Use JSON for a payload, JSON Lines for a log.

Can I convert the BBCode back to JSON Lines afterwards?

Not mechanically. BBCode keeps how the table looks, not what it held, so going back means reading the values off the page again. Keep the JSON Lines if you will need it.

Will my numbers still be numbers?

They will read the same, but BBCode stores them as text. Anything that sorts or sums the result will need to parse them first, and a leading zero or a currency symbol is the usual place that goes wrong.

What happens to nested values?

BBCode has no nested cell, so a list or object inside a JSON Lines value is flattened into a single cell rather than expanded into extra columns. Split it before converting if the parts need to be separate.

Is there a limit on file size?

No. The work happens on your own machine, so the limit is your machine's memory rather than an upload cap. A file with tens of thousands of rows converts in a second or two.

Is my data uploaded anywhere?

No. The parsing and generating are done by JavaScript running on this page. You can watch the network tab while you convert and see that nothing is sent.

Related conversions