Tablizer

Convert JSON Lines to PNG Online

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

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

A lossless image format. Text and thin lines stay exactly as drawn, which is what a table is made of.

Slides, chat messages, issue trackers, and anywhere a table has to travel as a picture rather than as data.

What changes when you convert JSON Lines to PNG

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.

The table is drawn from the data onto a canvas rather than captured from the page, so the whole thing comes out however long it is and however much of it is on screen. Column widths are measured from the content, alternating rows are shaded, and the scale is adjustable so a table for a slide or a print layout can be drawn at two or three times the size.

What carries over from JSON Lines to PNG

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

JSON Lines knows which of its values are numbers. PNG keeps only their appearance, so nothing downstream can sort or sum them without someone reading them back off the image first.

An empty cell and a missing one are the same thing in PNG, 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. PNG has only flat cells, so nested values are flattened into one cell rather than being spread across columns.

JSON Lines can be read one record at a time. PNG 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.

PNG 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.

Questions

How do I convert JSON Lines to PNG?

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 PNG 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 get the data back out of a PNG of a table?

Not without optical character recognition, which is a different kind of software with a different failure rate. An image of a table is pixels. If anyone downstream might want to sort or sum the numbers, send the table as well as the picture.

Can I convert the PNG back to JSON Lines afterwards?

Not mechanically. PNG 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 look the same, but PNG holds no values at all - only their appearance. Nothing can add up a column of a PNG without the numbers being read back out of it first.

What happens to nested values?

PNG 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.

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