Does this connect to my Portainer instance?

No. It is a local checklist helper. It does not call Portainer, Docker, or any server.

Should I paste production secrets here?

Processing stays in your browser, but secrets are still sensitive on shared machines. Prefer sanitized examples when possible.

Does it validate the Docker Compose file?

No. It scans variable references and env lines. Use Docker or Portainer validation for the final Compose syntax check.

flashman

Guides Blog All tools

← All tools

Portainer Env

portainer • docker • env • self-hosted

Environment variables

Docker Compose snippet (optional)

Variables

Compose refs

Needs review

Portainer env block

DOMAIN=app.example.com
TZ=UTC
APP_PORT=8080
DATABASE_URL=postgres://app:change-me@db:5432/app
POSTGRES_PASSWORD=change-me

Deployment checklist

# Portainer stack environment variables
DOMAIN=app.example.com
TZ=UTC
APP_PORT=8080
DATABASE_URL=postgres://app:change-me@db:5432/app
POSTGRES_PASSWORD=change-me

# Deploy checklist
- Confirm the stack name, compose file, and Git ref before updating.
- Paste variables into Portainer exactly once; remove duplicates first.
- Keep production secrets in Portainer or a secret manager, not in Git.
- Verify proxy labels, public hostnames, and exposed ports after deploy.
- Run a rollback plan before replacing a working stack.

# Compose variables found: APP_PORT, DATABASE_URL, DOMAIN, TZ
# Findings to resolve: 1

Findings

Placeholder value: POSTGRES_PASSWORD

Replace placeholder values before deploying a public service.

Variables not referenced by Compose

POSTGRES_PASSWORD may still be used by the image, but they are not interpolated in this compose snippet.

About this tool

Check Portainer and Docker Compose environment variables before deploying a self-hosted stack. The helper finds missing Compose references, duplicates, empty values, placeholder secrets, and public-looking secret names in your browser.

Your input is processed in the browser. We do not upload tool payloads to our servers.

Common use cases

Prepare a Portainer stack env block from a copied .env file.
Compare Compose ${VAR} references against the variables you plan to paste.
Build a deployment checklist for self-hosted apps, VPS services, and homelab updates.

Examples

Find a missing Compose variable

Paste a compose snippet using ${DOMAIN} and an env block without DOMAIN. The tool flags the missing value before Portainer deploys the stack.

Spot placeholder secrets

Values like change-me, password, and secret are highlighted so they do not reach a public cloud or VPS service by accident.

FAQ

Does this connect to my Portainer instance?: No. It is a local checklist helper. It does not call Portainer, Docker, or any server.
Should I paste production secrets here?: Processing stays in your browser, but secrets are still sensitive on shared machines. Prefer sanitized examples when possible.
Does it validate the Docker Compose file?: No. It scans variable references and env lines. Use Docker or Portainer validation for the final Compose syntax check.

Related guide

Prepare Portainer stack variables, Docker Compose references, secrets, domains, ports, and rollback notes before updating self-hosted services.

Read: Portainer stack environment variables: a safe deploy guide →