What's the difference between 看到&看见？

看到 is more commonly used than 看见 in everyday speech.

看到 implies a higher degree of certainty or that the speaker saw the entire event or action, while 看见 implies a less certain or more brief sighting.

看到 is often used when referring to a visual experience in general, while 看见 often refers to a specific object or person being seen.

someone can ask you do you see something and you can answer 看到了. It's more specific and it enphesis the fact that you are able to see something.

看见 simply you see something like you are observing

As I understand it, 看到 is used when you found something by looking, for example, when you loose your phone and are searching for it,when you find it you can say 看到了! , while 看见 is used when you observe something, for example, you are taking a walk, just looking around, when you see an old friend, you could say 今天我看见了一个老朋友

I never knew this as well. thank you for asking this 😅

They are almost the same. But 看到 is more oral than 看见。

看到 places more emphasis on the result and the ending of the action, while 看见 tends to show the perceived situation.

In a way those two words can be used interchangeably.
【1】看见 “见”对“看”的结果的补充
In this word，“看”it’s an action，“见”is the result。
Eg:我没看他。
(意思是我甚至没有做看他这个动作)
It means I didn't even do the action of “看”.
Eg:我没看见他。
(意思是我做了看这个动作，但是结果是我没看见。)
It means I did the action of“看”, but I didn't see him.
【2】看到“到”也是“看”的结果的补充
In this word，“看”it’s an action，“到”is the result。
而且是有目的，想去看，结果看到了
And with a purpose. I wanted to see it, and I saw it
Eg:我看到他了。

看到 and 看见 both mean "see, catch sight of", and express the result of seeing, they are exchangeable.

But 看到 also means "looks forward to" express expectedness, while 看见 doesn't have this meaning.

eg:
人们看到希望。(People see hope.)
人们看见希望。(People see hope.)

The two have slightly diffrent:

看见希望, emphasize what someone has seen, some actually happened things, and then deduces a promising future.
看到希望, emphasize someone's expectation.

Usually these 2 expressions are identical.
But 看到 indicates that the subject might expect something. For example you have wanted to visit the Great Wall for a long time and you finally did it. Then you could say 我终于看到了长城, meanwhile 我终于看见了长城sounds however a little bit weird, although it is also grammatical.

common ground.: they are means the result of looking (concrete objects )

The difference: 看见+more objects（something abstract ） 例如：we can say: 看到现象、看到事情的本质。