<p>Can we consider these statements to be true?</p>
<ul>
<li><p>Hard forks and soft forks are both backward compatible, but only soft forks are forward compatible.</p>
</li>
<li><p>However, backward compatibility in soft forks can be fragile if relatively low hash power supports the new software. For example, if a modified pre-taproot node mines a segwit-v1 input transaction.</p>
</li>
</ul>

CC BY-SA 4.0
2024-12-25T10:02:03.530Z
This question is similar to: [What is a soft fork? What is a hard fork? What are their differences?](https://bitcoin.stackexchange.com/questions/30817/what-is-a-soft-fork-what-is-a-hard-fork-what-are-their-differences). If you believe it’s different, please [edit] the question, make it clear how it’s different and/or how the answers on that question are not helpful for your problem.
RedGrittyBrick
CC BY-SA 4.0
2024-12-25T19:51:58.117Z
@RedGrittyBrick, Thanks for the link. I had read that previously. However, my main question is about backward compatibility. Can hard forks be backward compatible? I've seen various sources, including a tweet by murch, stating that hard forks are also backward compatible.
hcb2
CC BY-SA 4.0
2024-12-25T20:01:29.467Z
Can we provide an example of how BCH can demonstrate backward incompatibility? For instance, would the mandatory segwit sighash algorithm or the ForkID flag serve as such an example?
hcb2
CC BY-SA 4.0
2024-12-25T20:34:13.080Z
Can this be considered: If a hard fork is backward compatible, there is a possibility of a wipeout?
hcb2
<blockchain-fork><soft-fork><non-standard-transaction>
Backward and forward compatibility
hcb2
# Backward and forward compatibility

(Asked by: username_0 on 2024-12-22)

Can we consider these statements to be true?

* Hard forks and soft forks are both backward compatible, but only soft forks are forward compatible.
* However, backward compatibility in soft forks can be fragile if relatively low hash power supports the new software. For example, if a modified pre-taproot node mines a segwit-v1 input transaction.

**Tags:** blockchain-fork, soft-fork, non-standard-transaction

> **Comments:**
> **username_1**: This question is similar to: [What is a soft fork? What is a hard fork? What are their differences?](https://bitcoin.stackexchange.com/questions/30817/what-is-a-soft-fork-what-is-a-hard-fork-what-are-their-differences). If you believe it’s different, please [edit] the question, make it clear how it’s different and/or how the answers on that question are not helpful for your problem.  
> **username_0**: @username_1, Thanks for the link. I had read that previously. However, my main question is about backward compatibility. Can hard forks be backward compatible? I've seen various sources, including a tweet by murch, stating that hard forks are also backward compatible.  
> **username_0**: Can we provide an example of how BCH can demonstrate backward incompatibility? For instance, would the mandatory segwit sighash algorithm or the ForkID flag serve as such an example?  
> **username_0**: Can this be considered: If a hard fork is backward compatible, there is a possibility of a wipeout?  

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## 0 answers

