'Agnostic' means that you can't know if a god exists. 'Atheist' means you don't belief in a god. Those two things are not contradictory.
These are the most common uses of those words but you probably have different definitions, so please share your definitions to let us see where the contradiction is coming from.

It is not contradictory.
I go by and Agnostic Atheist.
Atheist because I in now way believe in anything supernatural, and especially a "God" figure.
Agnostic, because I can't prove it either way.

you really seem to obsess over this atheist vs. agnostic issue you have

We mostly reject labels here.....

I don't so you must not have looked at my profile. There are dozens of threads posted on the topic if you'd like to attempt the search feature. I only want to meet Antitheists, so there's no hope here.

They are not contradictory, they are just two sides of the same coin, at least when it comes to the standard-issue, supernatural, invisible, interventionist, non-falsifiable deity.

Agnostics say you can't know if there's a god. (knowledge position: no knowledge)

Atheists say if you can't know, it's darned hard to form a supportable belief (belief position: no belief)

If you don't want to identify with the Atheist label (for example, because it's a buzz-kill if you want to openly socialize as such) that's fine. You don't have to. The above argument is a philosophical one, it's not some sort of religious dogma. Think you're not an atheist if you'd rather not be that. Just don't try to use your private definitions for the terms "agnostic" and "atheist" in a philosophical discussion.

It is not contradictory. It is complementary.

If one is to assert that there is no god, one must be prepared to present the evidence to support the claim. Because there is no evidence and the absence of evidence does not represent grounds to make such an absolute assertion, it is a fool's errand to make the claim. In that respect, I am an agnostic. At the same time, for my personal stance, there is nothing existing outside our reality either. I maintain that position simply because there is insufficient evidence to make that assumption, though that same lack of evidence does not validate my stance. So, I don't believe in gods, leprechauns, bridge trolls, Ouija boards, or that black cats crossing my path are going to result in bad luck, luck being something else in which I hold no belief. That does not mean I'm right. All it says is that I haven't seen sufficiently compelling evidence yet, but if it were to be presented I would certainly have to consider it.

Atheist just means lack of belief in a god. It does not mean that with compelling evidence you will not change your mind. So you can be both, you can be an agnostic deist too

The trouble with the English language is that we are always saying that we ARE this or that thing as though that thing were identical with ourselves and that is all we are. Usually our positions or opinions can not easily be described by a simple label.

Regarding the existence God as described in the Old Testament, I am not persuaded by any of the evidence I’ve seen. That skepticism is nothing but a characteristic of myself and should be of no concern to other people. It is a trivial thing that doesn’t even concern me and I am certainly not going to label myself an atheist. I am skeptical of many many ideas but I need not label myself in regards to those iffy ideas. Conversely there is no “burden of proof”. If someone is persuaded of something that is their business only.

I lean toward the concept of universal consciousness, not as something magical or supernatural but as a metaphysical idea that might someday become part of the body of scientific knowledge. If anyone wanted to label universal consciousness as “God” I wouldn’t object. But labels are just empty words if you don’t have knowledge of the thing you are labeling.

I don’t know about Universal Consciousness with absolute certainty. Am I supposed to say that I am an agnostic? If so, I decline. Sue me. What I do know is that there is an Ultimate Reality beyond the world of the senses. I reject any burden of proof. Sue me.

I don't believe in the supernatural and although I don't know for certain that no gods exist, I don't believe that which cannot be proven. Given that the burden of proof should fall on those who believe, I do not. I do not know with certainty that there are no unicorns, fairies, or mermaids either, but I am most certainly not agnostic on those counts.

I understand that I could be wrong, and I accept responsibility for that because if there is a god who allows the horrors, injustices, and suffering in this world, I do not want to spend eternity praising it.

Agnosticism is about whether or not you KNOW there is a God; Atheism is whether you believe there is any EVIDENCE for a God. You can see no evidence, and still not know, or think it is impossible to know for sure.

I'm an agnostic. With that being said labels are subjective and serve no purpose no matter the persons beliefs(or lack of).

It's just definitions. I wouldn't worry too much about it.

Ask or talk about what interests you.

Welcome to the asylum. Enjoy your stay.

Do you have something against atheists?
Not trying to be antagonistic, just curious.

Ready for a real head-exploder? I can (and sometimes do) choose to describe myself as "spiritual", on account of my commitment to Buddhism. I could even go so far as to use "religious", in the sense of a "religion" being "something strongly felt."

And yet the Buddhism I practice is not a "religion", according to the most common usage of the word--and I am most assuredly an atheist, as well as agnostic.

Look for Silvereyes's thread on this, if it's still available. The title has some language in it about "atheist vs. agnostic debate", IIRC.

Hi Erin, I have studied (and taught) the traditional arguments for and against the existence of God for decades and like you, I suppose, I'm a 50-50 agnostic.That is, I see no balance of evidence or logic either way for the existence of the orthodox theistic concept of God (=an omnipotent, omniscient, & omnibenevolent being).

I am listed as Agnostic only. When the site asks how certain I am there is no god, I have 0%. The same goes for how certain I am there is a god, 0%.

For me there are fact and evidence based probabilities that determine my thinking. It's probably not at 0%, but that number is infintesimally low based on the evidence ive seen.

If youre interested in literal, fact based discussion; youre going to need to do some digging, because based on what ive seen on this site so far; many here are not all that evidence or fact based in their thinking.

There are a lot of people here that are here for emotional support and simply do not buy into the fables of the major religions that are pushed mainstream.

That being the case you need to give your personal definition of the word agnostic, because like Brexit, it is a word that covers a multitude of definitions outside of the literal or etymological one.

I understand.

I like the way Bart Ehrman explains being both an agnostic and an atheist. Atheism confronts one’s lack of faith while agnosticism tackles the question of whether or not a god exists.

I may paraphrase this wrong, but I’ll admit it if I’m wrong:

Because of our limited knowledge of the universe, no one can be certain of the existence of some higher life form capable of creating life from inanimate matter. Lack of evidence of a deity prevents me from having blind faith in the existence of a deity, lack of knowledge prevents me from being certain that no deity exists. I am an agnostic atheist because I don’t know but I am scientifically open minded.

[ehrmanblog.org]

Maybe you are more of a skeptic

Yes, you are quite correct. The name of this website is agnostic.com, but it has been taken over by a large majority of atheists. And agnostics and atheists are quite different from each other, as I have learned during my time here. I am an agnostic, and definitely not an atheist.