Estimate password strength from length, charset mix, entropy heuristics, and a short common-password list.
- Free
- No signup
- Fast
- Privacy-friendly
What next?
Keep going with Password Strength Checker
Finish this check in the browser, then pick the path that matches how you work — another related tool, REST for apps, or MCP for agents.
- 1. Related check
After this result, run Secret leak scanner for the next signal.
Secret leak scanner - 2. Automate with API
Same job from your server with
Create free accountX-Api-Key. Free tier includes 500 credits/month. - 3. Hand off to an agent
Connect Cursor or Claude to ToolYour MCP — plan → run → verify.
MCP setup
What is Password Strength Checker?
Estimate whether a password is trivially weak before you ship signup rules. ToolYour Password Strength Checker scores length, character classes, rough entropy, and a short common-password list. It is a heuristic — not a substitute for breach databases or server-side rate limits. REST/MCP POST with { "password": "..." }. Prefer not to paste real production passwords into public forms.
What are common questions about Password Strength Checker?
Do you store passwords I check?
Inputs are processed for the score only. Still avoid pasting real high-value credentials when you can use a similar test string.
What does the score mean?
A rough strength label (very-weak → strong) from length, charset mix, and entropy heuristics plus common-password hits.
What are the key features of Password Strength Checker?
Actionable issues
Short checklist: length, case mix, digits, symbols, common list.
Entropy estimate
Bits estimate from length × charset size for relative comparisons.
How do you use Password Strength Checker?
Enter a candidate password
Use a test string when evaluating policy, not a live vault secret.
Tighten policy
Prefer longer passphrases; pair with your secure password generator.
Policy tip
Length beats complex short passwords. Encourage passphrases and a password manager; enforce breach checks on your server.
Free · API · MCPToolYour platform
Use Password Strength Checker three ways
The free Password Strength Checker on this page works in your browser. The same workflow is available via REST API for apps and via the remote MCP server for Cursor, Claude, and other agents — one API key, one plan, one quota. This tool is part of the security-apis module under Security Tools.
- 1Create a free accountGet an API key for REST and MCP — 500 credits/month on the free tier.
- 2Connect or callPaste the MCP URL into Cursor/Claude, or call REST with
X-Api-Key. - 3Same key & creditsBrowser smoke-checks stay free; API-backed runs share one monthly credit quota.
- Free in browserUse Password Strength Checker here — no account required.
- REST APICall from your server with
X-Api-Key. - Remote MCP serverSame job from Cursor or Claude via the ToolYour remote MCP server — one API key with REST.
Which secrets & auth tools sit in this cluster?
- Secret leak scanner
Heuristic API key and token leaks in pasted text.
- JWT decoder
Decode claims without verifying signatures.
- JWT signature verifier
Verify HMAC or asymmetric JWT signatures.
- Webhook signature verifier
GitHub, Stripe, or raw HMAC webhook checks.
- HMAC generator
Generate or verify HMAC digests.
Where does this job fit on ToolYour?
Where do you browse more security tools tools?
- Security Tools tools
Browse the full Security Tools category on ToolYour.
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Which toolkits include Password Strength Checker?
- Security Toolkit
HTTP security headers, TLS, cookies, CORS, redirects, DNS, secrets, JWT, passwords, hashes, HMAC, bcrypt, security.txt, SRI, and email auth — plus agent playbooks for full audits and ship gates.
- Developer Toolkit
JSON/XML/SQL formatters, encoders, UUID/timestamp/regex, JSON codegen, JWT minting, HTTP headers, request builders, cron, minifiers, and color conversion — plus security and text peers.