Question regards Seed phrase

hello

i have a question.

i have an old blockchain.info/com wallet from around end of 2013 beginning of 2014.

Back then i received a 12 seed phrase - so i checked 2 random words if they are listed in the BIP39 word list, and they do!

So my question is, if my seed phrase is now universal - meaning it can be imported on electrum for example, or did blockchain info back then used another kind of seed phrases, and they used the same word list from BIP39 just with another customizeation ( sum-check ) ?

And if so , since when did they start to use universal seeds?

https://www.reddit.com/r/Electrum/comments/udc2a7/can_you_recover_a_blockchaininfo_wallet_with_a/?rdt=44162
So if you create a blockchain.com (not info) wallet today, then it is BIP39 complaint. But if you created the blockchain.info wallet back in 2012 it would not be BIP39 complaint.
They switched to BIP39 / BIP44 compliance somewhere between 2012 and 2022.

Blockchain.info officially switched to the standard 12-word BIP39 seed phrases in late 2015/early 2016 with the launch of the third version of the wallet (V3 HD Wallet).
https://bitcointalk.org/index.php?topic=1357661.0

Blockchain.com started to generate 12 word BIP39 seed phrases in 2016.

Quote from: breyvin on May 16, 2026, 01:14:00 PM

So my question is, if my seed phrase is now universal - meaning it can be imported on electrum for example, or did blockchain info back then used another kind of seed phrases, and they used the same word list from BIP39 just with another customizeation ( sum-check ) ?

If you have an old blockchain.com seed phrase, you can't import it into other wallets.
If you have a new blockchain.com seed phrase, you can inport it into many other wallets including electrum.

Blockchain.com used a different wordlist before their 2016 upgrade and generated seed phrases using their own algorithm.

OP, I'm not sure if you tried to use the forum search, but I knew from memory where roughly to look at (took me a little searching to find LoyceV's recovery thread which I knew exists):

Quote from: LoyceV on August 26, 2018, 01:09:32 PM

...
Seed phrases, Word lists or Mnemonic phrases
Bitcoin wallets can be stored as seed phrases, usually 12 to 24 words long. The used words can be in several languages (thanks HeRetiK).

...
Blockchain.info: To recover an old legacy Blockchain.info wallet, read this topic and go here.
Blockchain.info: In some cases, Blockchain.info (now .com) shows a compressed private key while the address was uncompressed. Read this topic.
...

...

It is possible that you could find more topics that deal with the recovery of old mnemonic words wallets from blockchain.info. Newbie accounts have some limits with usage of forum search. I suggest to use https://bitlist.co/search to search this forum.

From above cited snipet it sounds like you would need your "wallet recovery mnemonics" (17-word recovery phrase). Do you have something like that?

Quote from: hosemary on May 16, 2026, 02:02:23 PM

Blockchain.com used a different wordlist before their 2016 upgrade and generated seed phrases using their own algorithm.

If the word list has been posted in public somewhere, it should not be too difficult for someone to make a "blockchain to bip39 translator" that just maps each blockchain.com word to the bip39 word for that same position.

I would be surprised if nobody has made such a tool or some other form of blockchain.com recovery software.

Quote from: NotATether on May 17, 2026, 10:10:37 PM

This is not possible.
It's not only the wordlist that is different. As I said in my previous post, blockchain.com old seed phrases were genereted using a different algorithm which is not even available to the public. Blockchain.com old seed phrases also included more than 12 words.

Quote from: hosemary on Today at 02:10:53 PM

Quote from: NotATether on May 17, 2026, 10:10:37 PM

Yeah even electrum seeds are completely different.
More details here
https://electrum.readthedocs.io/en/latest/seedphrase.html

This is not the same as a bip39 English x bip 39 portuguese (which can be freely translated, I even participated in translating the Portuguese one a few years ago)

Quote from: hosemary on Today at 02:10:53 PM

blockchain.com old seed phrases were genereted using a different algorithm which is not even available to the public.

Wouldn't it be about time they make this open source? What if someone still wants to recover their coins years or even decades from now?

Quote from: LoyceV on Today at 04:55:22 PM

Wouldn't it be about time they make this open source? What if someone still wants to recover their coins years or even decades from now?

Just a guess:
Maybe, there is nothing similar to BIP39 algorithm to be made available to the public at all and it's not technically possible to generate the keys without relying on their servers and just with a seed phrase.

If blockchain.com is not available for any reason, all the people having an old wallet there will lose their funds forever.

I'm new in this forum and forgive my ignorance, but why don't you install electrum or sparrow in an offline laptop and try it for yourself?

Quote from: greyplum on Today at 06:42:39 PM

I'm new in this forum and forgive my ignorance, but why don't you install electrum or sparrow in an offline laptop and try it for yourself?

Yeah, and search for several derivation paths. Even tools like iancoleman.io can work

There is a place to enter blockchain.info as Client parameter in the derivation path.

https://iancoleman.io/bip39/

Quote from: bitmover on Today at 06:50:43 PM

Yeah, and search for several derivation paths. Even tools like iancoleman.io can work

It may be worth mentioning that this works only if your blockchain.com seed phrase is BIP39.
If you have an old blockchain.com seed phrase, your only option is to use blockchain.com itself and there is no other tool that can calculate your keys.