Farewell vs So long

When to use each in English, with meaning, register, and examples.

Farewell

Top 5,000 (fairly common)

So long

Informal Top 2,000 (common)

Most formal: Farewell Most common: So long

	Farewell	So long
Pronunciation	🇬🇧 //fɛəˈwɛl// 🇺🇸 //fɛrˈwɛl//	🇬🇧 //səʊ lɒŋ// 🇺🇸 //soʊ lɔŋ//
Meaning	A way to say goodbye.	Goodbye.
Example	She waved a heartfelt farewell as the train departed.	I have to go now, so long!
Register	Neutral	Informal
How common	Top 5,000 (fairly common)	Top 2,000 (common)
Collocations	bid farewell, say farewell, farewell party	say so long, so long, friend, so long and farewell
Antonyms	greeting, welcome	hello, welcome
Common mistakes	Used too casually in everyday settings., Confused with 'farewell' as a noun and verb., Overused when a simple 'goodbye' would suffice.	Used in formal situations where a simple 'goodbye' is better., Misused by saying 'so long' when parting for a short time.
Usage notes	Use 'farewell' in formal situations or when parting for a long time. It's less common in casual conversations.	Used casually among friends. Not suitable for formal settings or professional goodbyes.

See it in real clips

The Lord Of The Rings › The return of the king

Farewell, Peregrin, son of Paladin.

The Lord Of The Rings › The Fellowship Of The Ring

I bid you all a very fond farewell.

The Lord Of The Rings › The return of the king

Farewell, Peregrin, son of Paladin.

The Lord Of The Rings › The Fellowship Of The Ring

I bid you all a very fond farewell.

Farewell

after so long, I had none.

Well, so long.

A Knight Of The Seven Kingdoms › S1 E1

So long as it holds my scabbard, it serves.

after so long, I had none.

Well, so long.

So long

Frequently asked questions: Farewell vs So long

What's the difference between Farewell and So long?

Farewell: A way to say goodbye. So long: Goodbye.

Which is more formal: Farewell and So long?

Farewell is the most formal of these.

Which is more common: Farewell and So long?

So long is the most common in everyday English.

Can you show an example of each?

Farewell: She waved a heartfelt farewell as the train departed. So long: I have to go now, so long!

Can I use Farewell and So long interchangeably?

Not always. Farewell and So long are related and overlap in some contexts, but they differ in register, how common they are, and usage, so swapping one for another can change the meaning or tone. Check the differences above before substituting.