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Does Dropbox compress photo files?

I'm sending full resolution photo files to clients instead of burning them on a disc, but I want to make sure they are the full resolution. I had a client that had pictures made at Walgreens, and they were pixely..I told her not to resize them at all o her end, but now I'm wondering if they are compressed at all and no longer full resolution. If so, I need to go back to discs.
Thanks!

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tonyaveniros

I uploaded a 107.5MB TIFF file to Dropbox using a desktop browser, then downloaded the file. I then compared the file in my download folder to the source file.

Both were exact matches down to the byte: 107,525,5436 bytes.

I then checked for JPG. Also an exact match 9,177,764 bytes.

Then I checked CR2 files (Cannon's proprietary file extension)

Drumroll...both files were 23,921,835 bytes.

If you are using some mobile app to upload your photos...switch to desktop if you care about such things, but blame the right party.

Last I checked, I do not work for Dropbox, nor do I own any stock. If you call someone a liar, you better be able to back it up at least as well as dropbox backs up your files.

All comments

Orla

Hi Silisia, Dropbox does not compress photos. Files are synced exactly as they are.

Ira1

so how come the hash and size change? I think I can see in the EXIF that you automatically change the orientation without asking, but how come the file is 0.5%-1% smaller than on my phone? what else is edited? and why can't I avoid the renaming?

Lu D.1

Holly, you're lying to us. I have the same experience.

Personal experience, Dropbox 3.8.6, Windows 10 Pro.

garry s.1

Yep, the file size definitely changes a little bit once the upload to Dropbox happens.

What's going on, Dropbox?

garry s.1

Someone's done some research on the images uploaded to dropbox and it appears that the images are being re-compressed upon upload. Hopefully the images on the original device aren't being harmed, too.

https://blog.night-shade.org.uk/2015/06/dropbox-iphone-camera-upload-changes-photos/

Tim F.20

I wrote that article, the originals are untouched on the device. The Dropbox App also adds a unique tracking ID to each photo uploaded via the App.

Ira1

Well, I have moved to a private installation of OwnCloud on my own private server. Can't trust Dropbox nor Mega to protect the privacy and integrity of my files, and real encrypted options are more pricey than running my own server. kinda sad...

Ray H.16

@Tim F. & @Ira,

I have been using dropbox since its inception. I have had the same questions as you both have. I am constantly looking for answers. Thank you for your input.

I do wonder, if just "binary difference"? Thats why they are "different" files...

Anybody? Hopefully an actual Dropbox engineer can answer...

Tim F.20

The tiles are significantly smaller. If you look at the blog post I wrote there is a GitHub repo, with a single image that has been via Dropbox, Google photos and iCloud.

If you look at the fine details there are differences. My main issue is the lack of honesty from Dropbox and the fact there is a mystery tracking number included in the photos.

Ray H.16

@Tim F

Have you tried to test other type of files? To see if we see the same type of binary differential, like lets say for a .doc or .pdf file?

Tim F.20

I'll see if I have time over the weekend to look at this.

There is also a variable I hadn't thought of which is the difference between uploading from a desktop client vs a mobile client. I tested the mobile photo upload and found the changes but I've not tried it with a desktop client.

Benna C.

The numbers don't lie. A photo file on my iPhone sent to my email account is 505 KB and 151 KB uploaded to DB. Please explain.

Randy & Linda R

I just checked. My original photos are 5184 X 3456. After placing them on DropBox and downloading them to the computer again, I have only 1024 X 683! The files are ruined!

Stephanie H.12

As a photographer, I have had many complaints that the dropbox files are not the high res images that I uploaded. In fact Facebook shows better quality than dropbox. This revelation has come during my busiest season and I am left scrambling around to purchase thumb drives, upload, and mail out over 20 galleries so people can get them in time to print for the holidays. I am beyond frustrated and will be canceling my account in the new year. I am literally sick to my stomach that I have delivered a low quality product and possibly lost business because of it. I have fellow photographers as clients who brought this to my attention so this is not just one person's opinion.

Robert M.

Dropbox, in our line of business we take a ridiculous amount of pictures and store/share them via dropbox. Our main concern is the amount of disk space that is consumed by our picture files. Once we've completed our report and used the original higher quality pictures, we generally try to compress the picture files to conserve disk space. However, as the phone manufactures continue to push higher resolution capabilities with each new phone release, the lower resolution/smaller picture files have been phased out. In order to eliminate the added step of compressing our picture files before uploading to dropbox, is there an option/setting within dropbox that will compress picture files/folders for us? Thanks!

Tim F.20

Robert, this was the key point I was making Google are upfront about recompressing your photos and offer a choice. You are either take the free storage with recompression or pay for storage and get unmodified files.

Apple are also very clear, we do not touch your photos (as I proved with checksums etc) but you pay for storage.

Dropbox charge for storage (beyond the fairly small free tier) but also recompress your photos, tag them with a unique ID and most importantly for me are not upfront and honest about this.

Angela P.12

I'm a photographer as well and decided to use Dropbox to upload a clients images a few days ago. I had noticed that the images looked low quality and that concerned me. Today i received and email from the client saying that the images looked like low res images. I did a side by side comparison of a dropbox downloaded image to an original image and there's a huge difference. BTW i pay to use dropbox so I'm very disappointed about this.

This will be my last time uploading high re images to dropbox.

Tori R.

I am a photographer as well. Dropbox needs to resolve this.

Lou D.3

I am a photographer as well. Dropbox needs to correct the downsizing of images otherwise Dropbox is useless. Please contact me with a fix ~

Sid

As an alternative, since DB is not resolving this issue, I suggest that you zip your files using WinRAR or WinZip before uploading it to any cloud storage (like Google Drive, etc.) as backup. This will somehow give you security on file quality. I hope this helps.

Tim F.20

The idea of compressing or encrypting the files is useful. The downside is it does break workflow and certainly can't be used with something automated like Dropbox's photo uploader.

Dave Carter

I just saw this post, and I can confirm to all that dropbox DOES NOT MODIFY photos.

The dropbox app on pc/mac doesnt even know what a photo is!

It syncs FILES it doesnt change your word document fonts, it doesnt change the format of the cells on your spreadsheet, it doesnt remove records from your database file, and it doesnt reimage your .jpg files (or any others)

The dropbox app simply sees files and uploads and syncs them.

It doesnt care what type of file it is,

FYI: dropbox does now additionally add a ads metadata to all files in the dropbox folder, but this is an alternative data stream and does not relate to the original data stream of the file.

Tim F.20

That is 100% not the case with the mobile photo uploader, which I have spent some time studying.

https://blog.night-shade.org.uk/2015/06/why-does-dropbox-add-a-unique-id-to-every-photo/

https://blog.night-shade.org.uk/2015/06/dropbox-iphone-camera-upload-changes-photos/

There are files available on github if you want to study them yourself.

https://github.com/TimJDFletcher/IMG_7082

Dave Carter

Tim : I just went to your test data, and i didnt find it very helpful,

the AFC.JPG is Image Size : 3264x2448

the dropbox.jpg is Image Size : 2448x3264

So between one and two its been rotated?

I also just uploaded some pics via my phone then compared them to the orginals and they are not different. I even did one on its side where the picture shows upright. Same result same file,

Mine is the android app tho so maybe a difference?

Tim F.20

The work flow I have as testing was:

Take image and on phone
Transfer image to computer / cloud service using different methods
Check image for changes using md5 or sha1 checksums

Photos can be the same resolution but a different quality, note the reduction in size in the Dropbox image from 2.8MB to 1.79MB with a loss of quality.

My issue is one of honesty as I explained in the post about this. I understand and accept that cloud services need to compress files but they also need to be clear about this.

Ray H.16

@Tim thank you for your tests. I'm wondering, should we take this up on Reddit? Maybe we can get more traction there since Dropbox, inc doesn't want to chime in.

Maybe we "the people" will have more info on there.

Hi Tim

I just double checked with one of our engineers and we don't compress photos at all. There might be something else changing the resolution during the upload time. If you want, please write us on http://www.dropbox.com/support with detailed description of your original file and how you see it on Dropbox, including the methods you're using to upload them, so our team can investigate it further.

Please do not disclose any personal information on the forum.

Thanks!

Tim F.20

Hi Ed,

Thanks for looking at this, could you check with your engineering team about the Camera Upload feature please. This is the feature that I have done detailed testing on and which is changing the file size and hash as well as adding the unique ID.

If your engineer could look at the write up that I did and explain the changes that would be great.

Aries E.

Hi.

I've just compare photos i've uploaded with Camera Upload and same photos I've pulled out from iPhone with iExplorer. For comparing I used dupeGuru with content binary compare.

About 300 of 560 photos was changed.

P.S.: no advertising here.

Tony K.5

Over the last few days, I've noticed a significant degradation of some images that I've uploaded to DB. Is it possible that there's a new compression algorithm at work? I understand that previously DB has stated that there's no compression at work. Maybe that's true, maybe it's not. I've always noticed some minor loss of clarity. But what I've seen over the last few days crosses be boundary of what's acceptable and what is not. Thoughts anyone?