CONFIGPAIR — ENVIRONMENT DIFF TOOL

Paste two env files. See every key one has that the other lacks.

Staging has a key production doesn't. A flag was left on after a debugging session. A URL still points at a test host. Configpair finds those differences in seconds — secrets masked by default, nothing uploaded, nothing stored.

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The Configpair comparison interface with two .env files pasted side by side, showing comparison results grouped into MISSING keys (red), CHANGED values (amber), and SAME entries (green). Credential values are masked by default for privacy.

01 / WHAT IT CHECKS

Config drift between environments is invisible until it breaks a deployment.

A key added to staging and never promoted, a URL still pointing at a test host, a flag left on after a debugging session — each is invisible until the thing it controls behaves differently in front of a customer. Configpair finds those differences in seconds.

MISSING keys

Keys present in one environment but absent from the other. This is the most common cause of a deployment that builds fine in staging and fails in production with a missing variable error.

CHANGED values

Same key, different value. A database host that still points at staging, a timeout set to 30s in one env and 120s in another, a flag that should have been toggled off.

02 / HOW IT WORKS

Nothing leaves this tab. The comparison happens where your data already is.

Configpair runs entirely in your browser. No server receives your env files. No database stores them. No third party touches them. The tool parses the KEY=VALUE format on each side, groups the results into MISSING, CHANGED and SAME, and highlights credential-shaped values so you can show the output on a screen share without exposing secrets.

  • No upload. The env content never reaches a network.
  • No account. There is nothing to sign up for. Paste and compare.
  • Secrets masked by default. Keys named SECRET, TOKEN, PASSWORD, KEY or similar show only the first and last four characters until you unmask them.
  • Export any time. Download a CSV or copy a plain-text report to your clipboard.

03 / WHAT IT COSTS

Free. No account needed. No trial that expires.

Configpair costs nothing. Every feature — paste, compare, toggle secret visibility, export CSV, copy report — is available immediately with no sign-up, no credit card, and no limit on how many files you compare. There is no free tier that caps features. The tool is what you see.

Why free? Configpair runs in your browser. There are no servers to maintain, no storage to provision, and no accounts to manage. Each comparison uses your machine's CPU, not ours. You pay nothing because it costs us nothing to run.

If your team needs something Configpair does not offer — automated comparison across many environments, CI integration, secret management audit — those are different products. This one compares two env files and does it well.

04 / WHAT IT DOES NOT COVER

Five things Configpair does not do, stated plainly.

No history

Configpair does not store past comparisons. Once you close the tab, the comparison is gone. If you need a record, export the CSV or copy the report before you leave.

No CI integration

This tool runs in a browser tab. It does not connect to GitHub Actions, GitLab CI, or any pipeline. A CI-integrated drift checker is a different product.

No secret manager

Configpair does not read from AWS Secrets Manager, Vault, or any external store. You provide both env files as text. What you paste is what gets compared.

No .env validation

The tool parses KEY=VALUE lines. It does not check whether a value is well-formed, valid JSON, a reachable URL, a correct port number, or anything else about the content.

No nested envs

Configpair compares exactly two files. If your workflow compares three environments (dev, staging, production), run it twice — there is no multi-file view.

No file loading

There is no file-upload button. Paste the content directly. This is deliberate: a file picker implies the browser reads a file from disk, which offers no advantage over copy-and-paste and adds UI surface for something that works trivially.

05 / EXAMPLE RESULT

One comparison, three categories, sixty seconds.

Here is what the output looks like when you compare a staging file against production. Keys with credential-shaped names are masked by default — shown as visible in this example, but hidden in the initial output until you choose to reveal them.

MISSING 2 CHANGED 3 SAME 4

MISSING (2)

Present in staging, missing from production (1)

FEATURE_EXPORT_PDF=false

Present in production, missing from staging (1)

SENTRY_DSN=https://...

CHANGED (3)

DB_HOSTlocalhost→prod-db.internal
API_TIMEOUT30000→15000
LOG_LEVELdebug→info

100%

Client-side — no servers

0

Accounts to create

Secrets masked

by default on screen share

TRY IT NOW

Paste two environment files and see the difference.

No upload. No account. Nothing stored. Paste the content of two .env files below. Configpair compares them immediately and groups the results into MISSING, CHANGED, and SAME.

Paste environment files above to see a comparison.

Results ready — export or copy above.

Configuration drift should not be a deployment risk.

Open the full comparison tool in a dedicated view, or use the widget above. Either way, your data stays in your browser.

Open full comparison tool →