SQL comment remover

Remove comments from
SQL code.

Remove comments from SQL queries and migration files online. Strips `--` line comments and `/* */` blocks while preserving string literals and identifier quoting.

Open the toolUse the API or CLI
Free, no signup Runs in your browser Instant, no upload Works on .sql files

Before and after

Real-world SQL code on the left. The same code with every comment removed on the right.

sql-input.sql
-- Migration: add 'archived' flag to orders table
-- Author: ops team

/* Add the column with a safe default. */
ALTER TABLE orders
    ADD COLUMN archived BOOLEAN DEFAULT FALSE NOT NULL; -- backfilled false

-- Backfill existing data
UPDATE orders
   SET archived = TRUE
 WHERE created_at < '2024-01-01' -- old orders only
   AND status = 'closed';

/* Verify count */
SELECT COUNT(*) FROM orders WHERE archived = TRUE; -- sanity
sql-output.sqlcleaned
ALTER TABLE orders
    ADD COLUMN archived BOOLEAN DEFAULT FALSE NOT NULL;

UPDATE orders
   SET archived = TRUE
 WHERE created_at < '2024-01-01'
   AND status = 'closed';

SELECT COUNT(*) FROM orders WHERE archived = TRUE;
Why use it

Built for SQL specifically.

Long-form SQL, schema migrations, ETL pipelines, reporting queries, is heavy with `-- explanation` lines. When debugging a query plan or comparing two versions in a code review, removing the comment noise lets you focus on the structure. Uncommenter handles both `-- line` and `/* block */` styles and never disturbs string literals containing dashes or asterisks.

  • -- line comments removed
  • /* */ block comments removed
  • Single-quoted string literals preserved
  • Identifier quoting ("name" or `name`) preserved
  • Auto-detected from .sql files
How it works

Strip comments in 30 seconds.

  1. 1

    Open the tool

    Head to uncommenter.com/tool. Nothing to install. Nothing to sign up for.

  2. 2

    Paste your SQL code

    Drop your .sql file in, or paste code into the editor. Auto-detection picks up SQL from the extension or file content.

  3. 3

    Click 'Remove Comments'

    The parser walks every character with a real state machine, strings, regex, and other context-sensitive parts are detected and left alone.

  4. 4

    Copy or download

    Grab the cleaned output. Your code never left your browser.

FAQ

SQL questions, answered.

Does it handle string literals with dashes?

+

Yes. SQL strings are single-quoted, and the parser tracks string state, so 'a -- string' is left alone.

What dialects are supported?

+

All standard SQL dialects, PostgreSQL, MySQL, SQLite, MSSQL, Oracle, BigQuery, Snowflake, share the same comment syntax (-- and /* */), so the same engine works for all of them.

Will it keep doc-style headers?

+

Headers using -- or /* */ are removed by default. If you want to preserve a license or migration metadata block, add it back via your build tool after stripping.

Other languages

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Try it on your SQL code now.

Free forever. No signup. No upload. Runs entirely in your browser.

Open uncommenter