It's not worth it
A very close synonym, sometimes perceived as slightly more formal. 'It doesn't deserve the effort.'
Means 'There's no point' or 'It's pointless.' Use when an action is futile or won't produce a result.
A more direct and literal phrase: 'It's a waste of time.' Use when the main resource being lost is time.
I wanted to go to the concert, but the tickets are very expensive. It's not worth it.
We can try to fix the old phone, but there's no point, it's already very slow.
Arguing with him about that topic is a waste of time; he's never going to change his mind.
The car trip takes ten hours. It's better to take a plane, it's not worth driving that much.
'No vale la pena' is the most widespread and universally understood phrase.
'No merece la pena' is equally, if not more, common than 'no vale la pena'. Both are used and understood.
The expression 'no tiene caso' is extremely common and often used interchangeably with 'no vale la pena' to mean something is pointless.
While 'no vale la pena' is standard, you may also hear the colloquial 'No da para tanto,' which suggests something isn't worth the fuss or effort.
'No vale la pena' is the standard expression. 'No se justifica' (it's not justified) can also be used in similar contexts.
Saying 'No es valor la pena' or 'No es la pena'. — This is a direct translation error. The phrase is an idiom that uses the verb 'valer' (to be worth), not 'ser' (to be). The correct structure is always 'valer la pena'.
Using the wrong conjugation, like 'Yo no valo la pena'. — The subject of the sentence is the action or thing, not the person. Therefore, the verb is always conjugated in the third person: 'vale' (present), 'valió' (past preterite), or 'valía' (past imperfect). For example: 'Esa película no vale la pena'.
Translating 'worth' as 'digno', as in 'No es digno de la pena'. — While 'digno' means 'worthy', it's not used in this idiomatic expression. 'Valer la pena' is a fixed phrase that doesn't change.