Empty Value Detector

An empty value in a .env file is the quietest bug in configuration. The key exists, the parser does not complain, and the app boots — then behaves as if the feature never existed, because process.env.KEY is just an empty string.

The Empty Value Detector scans for four flavours of nothing: a bare KEY=, a value made only of whitespace, an explicitly empty quoted value KEY="", and the commented-but-present #KEY=. Each is reported with its line number and its kind, so you can decide whether it is a real gap or an intentional switch.

An allow-list toggle marks keys you keep empty on purpose, keeping the report honest. Everything runs in the browser.

• Four empty kinds: bare, whitespace, quoted-empty, commented.
• Line numbers: each occurrence is located exactly.
• Severity hints: suspicious vs intentional-looking.
• Allow-list: mark keys that are empty on purpose.
• Summary counts: empties found and lines affected.
• Copy or download: export the report.
• Instant: re-checks as you type.
• Private: 100% in-browser.

1. Paste your .env into the input, or load the sample.
2. Add any intentionally-empty keys to the allow-list box (one per line).
3. Click Scan. Every empty value appears with its line and kind.
4. Fill in the real gaps or confirm the intentional ones.

Example 1 — Broken webhook. PAYMENTS_WEBHOOK= quietly disables a callback. The detector flags line 12 so the team finds it before staging tests fail.

Example 2 — Whitespace slip. An editor wrote REDIS_URL= followed by trailing spaces. The value parses to empty and every cache call falls back.

Example 3 — Empty quotes. A contributor committed DB_PASSWORD="" instead of the real secret. The quoted-empty kind is surfaced separately.

Example 4 — Commented switch. A key moved to a feature-flag service, leaving #DEPRECATED_KEY= in the file. The detector finds it during cleanup.

Example 5 — Intentional empties. A team uses DEBUG= as an off-switch; adding DEBUG to the allow-list keeps the scan green.

• Finds silent failures: empty strings hide broken config.
• Kind-aware: whitespace differs from quoted-empty.
• Intentional or not: allow-list separates design from accident.
• Line-exact: jump straight to the fix.
• Private: never leaves the page.
• Free: no account needed.