SQLens: LeetCode Helper & Study Notes

LeetCode notebook for SQL & DSA: turn your solutions into study notes, tag topics, export a revision PDF for interview prep.

SQLens is a free LeetCode extension that turns the solutions you already write into revision notes, tracks which topics you are actually weak at, syncs every Accepted submission to your own GitHub repo, and exports the whole notebook as an interview-prep PDF. Built for LeetCode SQL 50 and data analyst interview prep, and it works on every problem type — arrays, dynamic programming, graphs, DSA. WHY PEOPLE INSTALL IT You finish a problem, you never write it up, and three weeks later you solve it again from scratch. Prep that lives in a closed tab is prep you lose. SQLens keeps a notebook of your own work so revision takes minutes instead of a re-solve. WHAT YOU GET • One-click capture — save the problem you are on with a button or Alt+Q • AI study notes from the code YOU wrote — intuition, approach, complexity • 5 AI generations free with no setup at all, no API key, no signup • Automatic topic tagging — joins, subqueries, window functions, CTEs, aggregation, plus LeetCode's own tags • Progress and weak topics — scored from your wrong submissions and the times you reached for a solution, not from how many problems you finished • GitHub sync, unlimited and free on every tier — each Accepted solution is committed to a repo in your own account, public or private, with your notes and a README that indexes everything by topic with your solved stats • Printable revision PDF of your whole notebook • Optional AI solutions behind a thinking timer you set yourself — once locked it cannot be shortened, paused, or cancelled • Works in any language the LeetCode editor supports FREQUENTLY ASKED Is SQLens free? Yes. The free tier gives 12 captures, 12 AI write-ups, 12 AI solutions and 12 PDF exports every month, on any problem type, and GitHub sync with no cap at all. Pro removes the limits for $2.50/month or $12/year, in your local currency. Do I need an API key? No. Your first 5 AI generations run with zero setup. After that you paste a free Groq API key, which is stored on your machine and sent only to Groq. Does it work for LeetCode SQL 50? Yes — that is what it was built for. Every query is tagged by what it uses, so your SQL practice notes show you your own patterns across the list. Does it work for DSA and algorithm problems too? Yes. Captures, notes, tagging, GitHub sync and PDF export work on every LeetCode problem, in any language. Does it save solutions to GitHub automatically? Only after you connect GitHub and choose a repo. Then every submission LeetCode marks Accepted is committed with your notes. Nothing is pushed before you connect it. Is it cheating? Does it touch my LeetCode account? No. SQLens never submits, posts, or changes anything on LeetCode. It reads the problem title and the code you typed, and only when you press a button. What about privacy? Nothing is captured automatically — every save is a button press. Your notebook, notes, queries and counters stay in local browser storage. Data leaves your device in exactly three user-initiated cases: an AI generation (to Groq), restoring a purchase (your email), and GitHub sync (to your own repo). No analytics, no tracking, no telemetry. Premium problems are never captured, and exports contain your own work plus a link to the problem, never the problem text. GOOD FOR SQL interview preparation • data analyst and data engineer interviews • LeetCode SQL 50 and database problems • DSA and coding interview prep • building a public solutions repo on GitHub • spaced revision before an onsite SQLens is an independent study tool. It is not affiliated with, endorsed by, or sponsored by LeetCode.