BIP39 Seed Phrase Validator
Check the structure of a BIP39 phrase without sending it to a phrase API. Use real wallet phrases only in a trusted offline environment.
What the validator checks
A BIP39 validator checks three things: valid word count, English wordlist membership, and checksum. It does not check balances, derive addresses, or prove that a phrase was generated safely.
Open the validatorValidation results explained
| Status | Meaning | What to do |
|---|---|---|
| Valid | Word count, wordlist, and checksum pass. | Still treat it as sensitive. Valid does not mean funded. |
| Bad count | The phrase is not 12, 15, 18, 21, or 24 words. | Check missing words, extra spaces, or copied notes. |
| Unknown words | One or more words are not in the BIP39 English list. | Check spelling, language, punctuation, and OCR errors. |
| Bad checksum | Words are real BIP39 words, but checksum does not match. | Do not trust the phrase until the error is resolved offline. |
Do not validate a real wallet phrase online
A seed phrase is enough to recover a wallet. If a malicious page, extension, clipboard tool, or network script captures it, the wallet can be compromised. YSeed avoids phrase APIs, but the safest rule remains simple: real wallet phrases belong offline.
Validator FAQ
What does a BIP39 validator check?
A BIP39 validator checks the phrase word count, confirms every word belongs to the selected BIP39 wordlist, and verifies that the checksum bits match the encoded entropy.
Is it safe to paste a real seed phrase into an online validator?
No. Use online validators only for demo or test phrases. Real wallet recovery phrases should be verified in an offline environment you control.
Does a valid checksum mean the wallet has funds?
No. A valid checksum only means the phrase is structurally valid BIP39. It does not prove that a wallet exists, has funds, or was generated safely.