Node types
Every node type is compared with 1,100+ real n8n node definitions. Invented or misspelled types, the cause of "?" nodes, are flagged, and wrong letter case is fixed.
Free tool · No sign-up
n8n Workflow Validator
Paste or drop any n8n workflow JSON, from n8n, ChatGPT or Claude. The validator finds node types that don't exist, broken connections and missing settings, fixes the safe mistakes automatically, and shows exactly what it changed.
1,100+ real node definitions
Runs in your browser
Nothing uploaded
Ctrl + Enter
Stays in this browser
See Gydmation build the workflow for you
This is the Gydmation app. Pick a request to watch an example run, validated live.Example runs, checked live by Gydmation's validator in your browser · Gydmation AI can make mistakes — verify workflows before activating
The validator finds mistakes. Gydmation stops them happening.
Describe the automation in one sentence. Gydmation builds it from 1,100+ real n8n node definitions and nearly 2,000 curated templates, asks when a detail is missing, checks it, and deploys it to your own n8n.
Free plan · No credit card · Self-hosted: your workflows and keys stay on your computerWhat the n8n workflow validator checks
It is the same validator Gydmation uses on every workflow it builds, running in your browser. It checks the workflow file itself; it can't test your credentials or live APIs, so run the workflow once in n8n after importing.
Connections
Connections that point to a node that doesn't exist, nodes that nothing connects to (so they never run), and duplicate node names.
AI agents
An AI Agent or chain without the language model it needs, AI sub-nodes wired into the wrong port, and sub-nodes connected to nothing.
Required settings
Emails with no recipient, Gmail bodies in a field Gmail ignores, Google Sheets with no spreadsheet or sheet, updates with no column to match on.
Data and expressions
Expressions missing the leading "=" (fixed automatically), Set fields with no value, and references to fields that the previous step doesn't produce.
Schedules and credentials
Schedule Triggers with no timing rule, legacy Cron nodes, a missing workflow timezone, the wrong credential type, and the accounts you'll need to connect.
Common n8n import errors and how to fix them
The problems people hit most often when importing a workflow, especially one written by ChatGPT or Claude.
Nodes show a "?" icon after import
n8n doesn't recognise the node type: it was invented by the AI, misspelled, or belongs to a community node that isn't installed on your n8n. The workflow can't run until each one is replaced with a real node.
The validator names each unknown node, and fixes letter-case mistakesCould not find property option
A parameter value isn't one of the options that node version accepts, usually because the JSON mixes fields from an older and a newer version of the node. Open the node in n8n and pick the option again, or rebuild the node from the current version.
Partly: the validator checks node types and key settings, not every option value"The file does not contain valid JSON data"
The text isn't valid JSON: often a missing bracket at the start or end, a trailing comma, or explanation text copied along with the JSON. Copy the whole workflow from the first { to the last }.
Steps that never run
A connection names a node that isn't there (often a one-letter typo in the name), or a node isn't connected to the trigger at all. n8n imports it without complaint, but those steps are silently skipped.
The validator removes dangling connections and lists unreachable nodes{{ $json.email }} arrives as plain text
Expressions in n8n start with "=". Without it, the field sends the literal text instead of your data. In the editor, switch the field from Fixed to Expression.
The validator adds the missing "=" automaticallyA schedule runs at the wrong time
If the workflow has no timezone, n8n uses the server's default (America/New_York on self-hosted n8n unless it's changed), so "9am" may run hours early or late. Set it in Workflow settings → Timezone, then check the next run time.
The validator warns when a scheduled workflow has no timezoneNode does not have any credentials set
Credentials never travel inside a workflow file, so every imported node that talks to an app needs its account connected in n8n. Open the node and choose or create the credential.
The Summary tab lists every account to connectHow to validate an n8n workflow
- Get the JSONIn n8n, open the workflow and choose ⋯ → Download, or copy the JSON from ChatGPT or Claude.
- Paste or drop itPaste it into the editor above, drop the .json file on it, or use Open.
- ValidatePress Validate (or Ctrl + Enter). Errors, automatic fixes and setup steps appear on the right, linked to their lines.
- Import the fixed versionDownload the fixed JSON and import it in n8n (⋯ → Import from File, or paste onto the canvas). Connect your accounts and run it once.
Questions
Is my workflow uploaded anywhere?
No. The validator runs entirely in your browser and the workflow is never sent to Gydmation or anyone else. Your last workflow is kept in this browser's own storage so it's still there when you come back; Clear removes it.
Is the n8n workflow validator free?
Yes. Free and unlimited, with no account.
Does it work with workflows from ChatGPT or Claude?
Yes, that's what it was built for. AI-written workflows often use node types or parameters that don't exist in n8n, and the validator checks them against the real node definitions.
Which n8n versions does it support?
It checks against the 1,100+ node definitions Gydmation uses. A node added to n8n very recently may not be included yet. Community nodes that aren't part of n8n are reported as unknown, because n8n can't run them until they're installed.
What can't it check?
Your real credentials, live API responses and data from your accounts. After importing, connect your accounts in n8n and run the workflow once to confirm it works.
Can it check a workflow already in my n8n?
Yes: download it from n8n (⋯ → Download) and open the file here. To check, fix and deploy workflows directly in your n8n, use the Gydmation app or the Gydmation MCP server in Claude or Cursor.
How is this different from Gydmation?
The validator reviews a workflow that already exists. Gydmation builds the workflow for you from a plain-English sentence, validates it the same way, and deploys it to your n8n.
Stop fixing workflows. Describe them instead.
Gydmation turns one sentence into a working n8n workflow, built from 1,100+ real node definitions, validated like this, and deployed to your own n8n.
Free plan · No credit card · Self-hosted: your workflows and keys stay on your computer