Lua Formatter
Paste messy or minified Lua and get clean, consistently indented code — block structure re-indented, commas normalized, blank lines collapsed, and optional quote-style normalization. Works on any dialect (5.1-5.4, LuaJIT, Luau). Runs entirely in your browser; nothing is uploaded.
About this tool
The Lua Formatter pretty-prints and re-indents a Lua script so it is easy to read,
review and diff. Paste one-line, minified or inconsistently indented Lua and it rebuilds
the source line by line: leading indentation is recomputed from Lua block structure —
function / then / do / repeat and the ( [ { bracket family open a level,
end / until and the matching closers close one, and else / elseif dedent their own
line. Commas and semicolons are normalized (no space before, one space after), runs of
blank lines collapse to a single blank, and trailing/leading blank lines are trimmed.
It is dialect-agnostic and forgiving: instead of parsing the script against one Lua
grammar and rejecting anything unusual, it reformats the token stream, so it works on Lua
5.1–5.4, LuaJIT and Luau. Long strings ([[ … ]], [=[ … ]=]), line comments (-- …)
and long comments (--[[ … ]]) are preserved verbatim — their interior is never touched —
and a keyword that happens to appear inside a string (print("end of file")) never affects
the indentation.
Worked example
Input:
if x then
print(1)
end
Output (indent 2, spaces):
if x then
print(1)
end
Options
- Indent — spaces of indentation per nesting level, 1 to 8 (default 2). Ignored when the indent character is a tab.
- Indent character — indent with spaces (the default) or a single tab per level.
- Quote style —
preserve(the default, keep each short string's own quote),double(normalize to"…"), orsingle(normalize to'…'). Quotes are re-escaped as needed — converting"don't"to single quotes yields'don\'t'. Long strings[[ … ]]are never requoted.
Limits
This is a re-indenter / beautifier, not a full pretty-printer. It never wraps long
lines at a column width, never adds or removes line breaks within a statement, and never
renames, reorders or drops anything — only leading indentation, comma spacing and blank
runs change. Because it does not parse a grammar, it will happily format invalid Lua (the
output stays invalid). Indentation is capped at one level of change per line, which keeps a
line that opens several blocks at once (run(function()) symmetric with the line that
closes them (end)).
Privacy
Everything runs locally in your browser via WebAssembly. Your code is never uploaded to a server.
FAQ
Will it tell me if my Lua has a syntax error?
No — by design. It reformats the token stream without parsing the script against a
grammar, which is what lets it accept any dialect and never reject unusual code. Invalid
Lua comes out nicely indented but still invalid; catching syntax errors is your Lua
interpreter's job (luac -p, lua, etc.).
Does it work with Luau and LuaJIT?
Yes. Because it is dialect-agnostic, LuaJIT and Luau extensions (compound assignment,
type annotations, continue, and other syntax) pass through as ordinary tokens — they are
re-indented alongside everything else rather than rejected. The block-opening and
block-closing keywords are the same across dialects, so the indentation comes out right.
Will formatting change my strings or comments?
Long strings ([[ … ]] / [=[ … ]=]), line comments (-- …) and long comments
(--[[ … ]]) are preserved byte-for-byte — their interior is never re-indented or
touched. Short strings are only changed if you pick a Quote style other than
preserve, and then only the delimiter changes (with escapes fixed up); the text inside is
kept intact.
Can it minify Lua onto one line?
No — this tool is a beautifier, not a minifier. Setting the indent to 1 still keeps every statement on its own line. Collapsing code onto a single line (and stripping comments) is the reverse operation and would need a dedicated minifier.
Why didn't a deeply nested line indent further?
Indentation changes by at most one level per line. This keeps lines that open several
blocks at once — like run(function() — symmetric with the single line that closes them
(end)), which is how idiomatic Lua callbacks are written. Statements that genuinely nest
one block at a time (if inside for inside function) still indent one level each.
Developer & Automation Access
Run it from the terminal
Same engine as this page, headless — via the gizza CLI:
gizza tool lua-formatter "if x then
print(1)
end"New to the CLI? Get gizza →
Open it by URL
Pre-fill and auto-run this tool with query parameters — the names match the API/CLI:
https://gizza.ai/tools/lua-formatter/?input=if%20x%20then%0Aprint%281%29%0Aend&indent=2&indent_char=space"e_style=preserveMachine-readable descriptor: tool.json — title + parameters JSON Schema for agents.