Why does 4plebs produce different hashes of what should be the same image?
By Anonymous | Updated 12/27/25(Sat)13:40:51
I will post an image here and show you what I mean. Currently when I drag and drop imagerel from file explorer into the Image Hash option under Search or insert post number on this page:
https://archive.4plebs.org/s4s
I get the hash ontP_Jup7csnhye6oTwY8g
When I open the file in my browser (MS Edge) I also get the same hash, ontP_Jup7csnhye6oTwY8g
Now, I will post this and show you what I am confused about, or what the problem is I suppose.
Your fortune: Godly Luck
>>12705511
*When I open the file in my browser (MS Edge) and drag and drop it I also get the same hash
is what I meant.
Anyways, now that I've posted this, clicking View Same on this post on 4plebs gives me the image hash j9Lzup2arxFD9wFETPKVaQ
Dragging and dropping the image from its page on 4plebs also gives me the hash j9Lzup2arxFD9wFETPKVaQ
But dragging and dropping it from this thread, unmaximized, gives me lBi-XgI20b4hdue2FSyleg
Maximizing the image in this page gives me
ontP_Jup7csnhye6oTwY8g
And dragging and dropping the image from its page here also gives me ontP_Jup7csnhye6oTwY8g
My question at the end of the day is why 4plebs has a different has (do they compress images?) and also how I can take an image like this and get the hash 4plebs would get of it without uploading a post of it like I just have. Because if I am looking for postings of a particular image, I may not have already found a post with the image, and I won't be able to go into the archive and "View Same" it.
For the record I'm not actually looking for other posts with picrel both because I just am not and also because there's already a post in the 4plebs archive with this image. I think a few years ago some fags on /v/ were embedding porn in images and mods had to put a stop to that. Hashes have been weird since then. >>12705511
>>12705521
correct me if I am wrong
you have an image and want to find the hash that would be given to said image without uploading it here
Your fortune: （ ´_ゝ`）ﾌｰﾝ >>12705511
because racecar
Your fortune: Good news will come to you by mail >>12705569
Yes >>12705576
the hash algorithm used is md5, use an online md5 file checksum, make sure it is set to base64. That should give you the hash. Come back if it works, if it doesn't come back too, we can work through it
Your fortune: Average Luck >>12705581
I did so, and got the same hash that the 4plebs version didn't generate (ontP/Jup7csnhye6oTwY8g==)
er, well, it's not exactly the same but I'm guessing it's a stylistic difference, not really too familiar with hashes and base64.
website I used: https://geraudloup.github.io/online
Your fortune: Outlook good
so is this the result you wanted or did you want the hash that would be generated from an unmaximised image?
Your fortune: Good news will come to you by mail
>>12705599
The result I want is to be able to hash search an image I have on my computer on 4plebs. To do that I want to get the hash that would be generated from 4plebs' archive of my image. The hash that I got from that github page is accurate to the image, but is not the hash generated from 4plebs' archive of my image, which is what is generated when you click "View Same", which is j9Lzup2arxFD9wFETPKVaQ and which, when you search 4plebs' archive for, you get other posts with the same image
Which would be this: https://archive.4plebs.org/_/search
I can find plenty of other images with the same hash. But since 4plebs' archive of my image generates this hash, which is different than the hash generated from my original image, if I just search the hash of my original image, I get no results.
That would be this page (no results, from dragging my image in through file explorer): https://archive.4plebs.org/_/search
I probably shouldn't have mentioned the unmaximised hash because it's not exactly relevant but I though it might have something to do with the reason behind the fact these hashes are different. The unmaximised version is probably just compressed/smaller which is what I figured 4plebs' version is.
it's an old problem and it can"t be helped I think, but let me check the dubs in your thread: check
>>12705599
dubs check once more >>12705511
Check exif data if the image aspect ratio, and file format are same. If file explorer drag and drop adds exif/exim location data, I think 4chan will scrub User above has a smay-are-te add-vie-see too. also check the encoding of the string, the hash algorithm being used, and read the wikipedia article diagram on 1-way hash functions.
Then again. Double check everything yourself, because I'm an retarded, and everyone else might be some of that too, the universe is uncertain. Trust but verify. >>12705511
>Maximizing the image in this page gives me
>ontP_Jup7csnhye6oTwY8g
My bad, I don't read anything I just talk over everyone like a really wide asshole.
Aspect ratio. The minimized file is a thumbnail of the original, which is a different file, which will produce a different hash? >>12705511
interestingly, though you can clearly see that 4chan reports the image filesize to be 260 KB:
>260 KB, 1080x1350
... when I save it to disk it's only 230 KB. and the same is true when I examine the image properties in Firefox before saving the image. that doesn't happen with the 4plebs copy. not sure if you're seeing the same thing happen or how that could be. 4chan processs all images before posting
>>12706218
The file explorer drag and drop isn't giving a hash any different than 4chan's, the only thing that's different is the 4plebs one (and the minimized version but that is easily explained.) Between the 4plebs image and the original, the EXIF data is the same, there is however a difference in size, which someone else mentioned.
>>12706220
Yes that's what explains that part. But still there's something going on between the full image and 4plebs' version as they have different sizes and hashes.
>>12706526
I am, the original is 229 KB (235,174 bytes) but it shows as 260 KB for some reason on 4chan. 4plebs' version is 260 KB (266,510 bytes) which is what 4chan claims.
>>12706556
That could be the case but 4chan's image and my image both have the same hash while 4plebs' version has a different one. >>12706556
apart from stripping EXIF, what processing would it do? I expect it would mostly be read-only, looking for hashes of spam images and that kind of thing
>>12706999 (trips!)
>I am, the original is 229 KB (235,174 bytes) but it shows as 260 KB for some reason on 4chan. 4plebs' version is 260 KB (266,510 bytes) which is what 4chan claims.
how bizarre... I wonder if anyone on /g/ would be familiar with this bump for interest
Anonymous is a reporter from /s4s/