Does this replace EXPLAIN?

No. It is a schema-agnostic heuristic that flags common anti-patterns quickly. Confirm every change with EXPLAIN and your real data volume.

Why was my query scored poorly?

Each penalty comes from a specific finding (e.g. SELECT *, a leading-wildcard LIKE, or a missing WHERE). Read the findings list to see exactly what lowered the score.

Is my query uploaded?

No. Analysis happens locally in your browser.

SQL Performance Analyzer

Find performance anti-patterns in a SQL query and get ranked fixes

SQL query

Performance score

Grade C

3 findings

3 findings (1 high/critical). Prioritize the high-severity items for the biggest gains.

EXPLAIN cost estimate

Estimated total cost46/100

Scan complexity56

Predicate selectivity28

Sort / grouping54

Heuristic preview only. Run EXPLAIN against your database for planner statistics and actual costs.

Suggested indexes

Heuristic suggestions from WHERE and JOIN predicates. Verify with EXPLAIN and existing indexes.

CREATE INDEX idx_users_name ON users (name);

Findings & suggestions

high

LIKE with a leading wildcard cannot use an index

'%ada%'

A pattern starting with '%' forces a full scan. Consider full-text search, a trigram index, or restructuring so the pattern is prefix-anchored.

medium

SELECT * fetches every column

SELECT *

List only the columns you need. SELECT * transfers unneeded data and breaks when the schema changes.

low

ORDER BY without LIMIT

ORDER BY orders.created_at

Sorting an unbounded result set is expensive. Add LIMIT or paginate to bound the sort.

About this tool

Analyze a SQL query for performance anti-patterns and get a score plus ranked, actionable fixes. Free online SQL query analyzer, runs in your browser. SQL Performance Analyzer runs in the browser on DevTools. There is no signup, and your input stays on this device unless the tool explicitly performs a live network lookup.

What this tool does not do

SQL Performance Analyzer is a free in-browser utility, not a hosted API. It does not keep server-side history and is not a substitute for production verification in your own stack.

How do I use this tool?

How do I use SQL Performance Analyzer?
Open SQL Performance Analyzer, enter or paste your input, and copy the result. The page works without an account.

SQL Performance Analyzer

SQL query

Performance score

EXPLAIN cost estimate

Suggested indexes

Findings & suggestions

About this tool

What this tool does not do

How do I use this tool?

How do I use SQL Performance Analyzer?

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SQL query

Performance score

EXPLAIN cost estimate

Suggested indexes

Findings & suggestions

About this tool

What this tool does not do

How do I use this tool?

How do I use SQL Performance Analyzer?

Related guides

Two SQL Reviews Every Query Should Pass

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