Validate your cryptocurrency wallet seed phrase length instantly. Check BIP-39 mnemonic word counts for 12, 15, 18, 21, or 24 words. Private, secure, offline.
AI Generation Prompt
Free BIP-39 Seed Phrase Length and Word Count Validator
Overview
A high-performance, browser-based tool designed to verify the structural integrity of cryptocurrency mnemonic phrases. This utility enables users to instantly check if their seed phrase meets the standard BIP-39 length requirements (12, 15, 18, 21, or 24 words).
Technical Implementation Constraints
- Architecture: Single-file HTML5 (HTML + CSS + Vanilla JS).
- Zero-Storage Policy: Absolutely no
localStorage,sessionStorage, or cookies. The tool must operate entirely in volatile memory. - Sandbox Compatibility: Must function without external dependencies, though reliable CDNs for CSS (e.g., Tailwind) are permitted.
- Privacy: All operations are client-side. The tool must have no network calls (XHR/Fetch) to ensure user data never leaves the device.
Features
- Real-Time Analysis: A live word counter that updates as the user types or pastes text.
- BIP-39 Validation Engine: Logic that checks if the input length is one of the five accepted BIP-39 standards.
- Visual Feedback: Color-coded UI indicators (Green for valid length, Red for invalid/unsupported length).
- Clean Clipboard Operations: One-click clear and safe text handling.
- Instructional Overlay: A clear, non-intrusive guide explaining how to interpret results.
UI Layout
- Header: A clean, minimalist header displaying the tool name and a brief tag-line.
- Main Tool Area: A centered, responsive card containing:
- A large, monospaced textarea for input.
- A prominent counter display.
- A status indicator card showing the validation result.
- Content Section: A concise section explaining the BIP-39 standard and tips for secure backups.
Color Palette & Aesthetic
- Theme: Professional, bright "SaaS" light-mode aesthetic.
- Primary Background:
#F8FAFC(Slate 50). - Container Background:
#FFFFFF(White). - Primary Action (Button):
#2563EB(Blue 600). - Success/Valid:
#16A34A(Green 600). - Error/Invalid:
#DC2626(Red 600). - Typography: Sans-serif (Inter or system-ui) for readability; Monospace for seed inputs.
Animations & Micro-Interactions
- Transitions: Smooth 200ms transitions on hover states for buttons.
- Feedback: Subtle fade-in animations when the validation status badge changes.
- Responsiveness: Fluid grid layout that adjusts padding and font size for mobile devices, ensuring the textarea is thumb-friendly.
Spread the word
Files being used
Frequently Asked Questions
Everything you need to know about using this application.
Why is the word count of my seed phrase important?
The BIP-39 standard for mnemonic phrases requires a specific number of words to be mathematically sound. Most standard cryptocurrency wallets use 12, 15, 18, 21, or 24 words to generate the entropy needed for a private key. Having the correct number of words is the first step in ensuring your wallet backup is intact. If your count is outside these specific numbers, it is physically impossible for the wallet software to derive your addresses correctly.
Is it safe to enter my seed phrase into this tool?
Yes, this tool is designed for privacy. All logic is performed locally in your browser using pure JavaScript. No data is transmitted to a server, recorded in logs, or cached in browser storage. Because the application does not utilize a backend or any storage mechanisms, your information never leaves your local device. We recommend using the tool in an offline environment or an incognito window for added security.
Does this tool validate if the words are correct?
This application focuses on structural validation, specifically verifying that the total word count matches the BIP-39 standard requirements (12-24 words). It does not check if the words themselves are part of the official BIP-39 word list or if they form a valid cryptographic key. Its primary purpose is to help you quickly identify if you are missing a word, have an extra word, or if your backup is formatted incorrectly before you attempt recovery in your wallet software.
What should I do if my word count is incorrect?
If your seed phrase does not match one of the standard lengths, double-check your physical backup. Often, a word may have been skipped during transcription, or extra characters might have been added by mistake. If the count is wrong, do not attempt to import the phrase into your wallet app, as it will simply fail. Use this tool to verify the count until it hits a valid number of words (12, 15, 18, 21, or 24) before proceeding.
