SQL minifier — put a query on one line without its comments

How to use the SQL minifier

1. Paste your query or script into the SQL box. The sample has line comments, a block comment and a string containing --.
2. Tick Treat # as a comment (MySQL) if your SQL is for MySQL or MariaDB.
3. Copy the Minified SQL. Saved, Original and Minified show the size change in bytes.

What it does and when to use it

A query that reads well in an editor is often awkward elsewhere: inside a string in application code, in a JSON config, in a shell command, in a log line or in a URL parameter for a dashboard tool. Minifying puts it on one line and strips comments that might contain internal notes. It is also a quick way to compare two queries that differ only in layout.

To go back to a readable layout, use the SQL formatter. The XML minifier and CSS minifier do the same job for other formats.

How it works

The minifier reads the SQL one character at a time in your browser and tracks where it is:

• -- to the end of the line is a comment, and so is # when the MySQL option is on.
• /* … */ is removed unless it starts with /*+ or /*!.
• Quoted text in '…', "…", `…` and […] is copied whole, including doubled quotes such as 'it''s'.
• PostgreSQL dollar-quoted bodies, $$ … $$ or $tag$ … $tag$, are copied whole, comments and line breaks included.
• Any run of whitespace becomes one space. That space is dropped after , ( ; = and before , ) ; =.

Worked examples

These are the tool’s own outputs.

The sample query. Seven lines with three comments become:

SELECT id,name FROM users WHERE note='keep  --  this' AND created_at >='2026-01-01';

Saved: 45.5%, from 154 bytes to 84. The -- inside the string survives because it is not a comment there.

MySQL with # comments. SELECT name # MySQL note, FROM `users` and WHERE id IN (1, 2, 3); on three lines, with the MySQL option ticked, give SELECT name FROM `users` WHERE id IN (1,2,3);.

A PostgreSQL function. In CREATE FUNCTION f() RETURNS int AS $$ … $$ LANGUAGE sql; the body between the $$ markers keeps its line breaks and its -- body comment, because it is a string to the database. Nothing outside it needed changing, so the saving is 0%.

Limits and tips

• Keywords are not changed. Upper and lower case stay as you wrote them.
• No renaming or shortening of tables, aliases or values.
• Keep the readable version in your repository and minify copies for embedding.