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Lua Viewer

Open a Lua file and read it with syntax highlighting, side by side.

  • Free
  • No signup
  • Nothing uploaded
  • No watermark

Source

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Program output

407 B
Ctrl+Enter · Lua · runs in your browser

Press Run to execute the program. Output appears here.

Read in this tab. Nothing you paste or open is ever uploaded.

How to Use the Lua Viewer Online

Lua Viewer: before and after LUA A BEFORE LUA VIEWER LUA A AFTER

Runs Lua in your browser and shows what it prints, asking for io.read() input in the output pane, and errors reported by line — the whole interpreter is loaded as WebAssembly, so nothing is sent anywhere and it works offline once open. Lua is small and usually embedded — in games, in nginx, in editors — so the file you paste is typically a plugin or a script rather than a whole program, and being able to run the bit you have, with your own input, is what makes it readable.

No software to install Free Works on any device

Step-by-Step Guide to Using the Lua Viewer

  1. 1. Write or paste your program on the left — a working example is loaded to start from

  2. 2. Press Run (or Ctrl+Enter)

    When the program asks for input, the question appears in the output with a box — type the answer and press Enter, and it carries on.

  3. 3. Output appears beside the code

    errors name the line. Fix, run again, and Download the file when it is right.

Try it now

What is the Lua Viewer?

Runs Lua in your browser and shows what it prints, asking for io.read() input in the output pane, and errors reported by line — the whole interpreter is loaded as WebAssembly, so nothing is sent anywhere and it works offline once open. Lua is small and usually embedded — in games, in nginx, in editors — so the file you paste is typically a plugin or a script rather than a whole program, and being able to run the bit you have, with your own input, is what makes it readable.

LUA file

.LUA

Open a Lua file and read it with syntax highlighting, side by side.

Why Use an Online File Viewer?

Not every computer has the right program for a YAML, VCF, SRT or log file, and installing one just to look inside is a chore. A viewer opens the file in your browser and shows it neatly next to its source text.

“Sometimes you just need to see what is inside the file.”
  • No software to install
  • Data laid out as tables
  • Subtitles shown with timings
  • Code tried out in the page
  • Colour-coded source text
  • Contacts and calendars readable
  • Works on shared computers
  • Private files stay local

Popular Uses for Code and Data Viewers

People open these when a file arrives and nothing on the computer will show it.

  • Checking a JSON response Open a JSON or YAML file as a readable tree instead of one long line.
  • Reading contact backups See the names and numbers inside a VCF file exported from a phone.
  • Opening calendar invites Read the date, time and place in an ICS file before adding it.
  • Checking subtitles View SRT or VTT subtitles with their timings to spot a missing line.
  • Reading log files Scroll through a server or app log with the lines laid out clearly.
  • Previewing CSV and TSV Look at a data file as a table without opening a spreadsheet program.
  • Trying a code snippet Run a short Python or JavaScript example from a tutorial and see the output.
  • Viewing SVG graphics See how an SVG icon or drawing looks next to the markup behind it.

What You Can Do with the Lua Viewer

Highlighting follows the language’s real grammar rather than a list of keywords

Reads a file you have not yet decided to trust, without registering a handler for it

Why Use ToolXkit for Lua Viewer?

Your files stay with you

Everything runs inside your browser. Nothing you open or type is uploaded to a server.

File Viewers for Different Users

Developers

Inspect config, env and data files on any machine without an editor installed.

Programming students

Try small programs in Python, JavaScript or SQL without setting anything up.

IT support staff

Open logs, HAR files and settings files that users send in.

Office workers

Read contact, calendar and CSV files that arrive as email attachments.

Video editors

Check subtitle files for timing and text before a video goes out.

Data analysts

Glance at CSV, TSV, JSONL and GeoJSON files before loading them anywhere.

Best Times to View a File Online

A browser viewer is handy when you are:

  • Using a borrowed or office computer
  • Opening an unfamiliar attachment
  • Checking a file before importing it
  • Learning to code without installing
  • Debugging a settings file
  • Proofreading subtitle timings
  • Looking inside a phone backup
  • Reviewing a server log

Frequently Asked Questions

Answers to common questions about this tool.

Does this actually run Lua, or just colour the code?

It runs it. The page loads a real Lua interpreter into your browser, so the output pane shows exactly what your program prints — including runtime errors with the line number. Nothing is sent to a server; the interpreter runs inside the tab.

How do I give the program input for io.read()?

When the program reaches io.read(), a box appears in the output pane: type the line and press Enter, and the program carries on. io.read("n") takes the next number from what you type; io.lines() asks line by line. Press Run to start over.

What happens if my script loops forever?

The run is stopped after eight seconds and you are told so. The interpreter lives in a background worker, so a runaway loop never freezes the page — fix the loop and press Run again.

Can I use require, os or io.open?

The standard library is loaded, so string, table, math, os.time and os.date all work. There is no filesystem in a browser tab, so io.open and require for files on disk return errors rather than pretending; paste the module into the same file instead.

Does Lua Viewer upload my file?

No. The file is read by your browser and shown on screen without being sent anywhere. Config files with passwords, contact lists and logs remain on your own computer.

Do the online compilers run real code?

Some languages, such as Python, JavaScript, TypeScript, Lua and SQL, run inside your browser. For others, the page is mainly for reading and sharing the code, so read the note on that page to know what to expect.

Does Lua Viewer cost anything or need a login?

Neither. There is no fee, no sign-up and no cap on how many files you open. It works the same on a work laptop, a home computer or a phone.

What if my file is very large?

Large logs and data files depend on your device’s memory, because the whole file is read in the browser. If a huge file feels slow, try a computer with more memory or view a smaller part of it.

Can I open a file from my phone?

Yes. Use the file picker to choose it from your phone’s storage or a downloaded attachment, and the contents appear on the page. A larger screen is easier for long files, but everything works on mobile.

Further reading

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