What is the appropriate file format for e-book covers on Kindle
October 15, 2014 3:16 PM Subscribe
In a nutshell, I'm trying to figure out how to make my Kindle book cover the proper file size at the lowest resolution and appropriate pixel size, and I'm coming up with a lot of conflicting and confusing suggestions. Anybody who has personally done this with successful file formatting results, please help.
I'm about to publish a short story (approx. 17K words) to Kindle Direct Publishing for the first time, and I'm having trouble figuring out exactly how to properly format the book cover file. I've extensively researched this online (and read KDP's formatting instructions) and am running into a lot of conflicting suggestions. I am looking for responses from people who have first-hand experience publishing books to KDP with successful file formatting results.
The main problem I'm running into is that, according to KDP's instructions, a book cover should be 1563 x 2500 pixels. (As a side-note, this 1563 x 2500 pixels doesn't seem to compute to the standard 6" x 9" cover of a printed book.) When I size the cover to these specs, it's around 4.2MB, even at a 72dpi. When this is added to the size of the .doc file of the story, the overall file size is near 5MB. At 300dpi, it's over 5MB. I'm further confused because when you look at the file sizes on books listed on Amazon, not many, especially short stories, are as big as 5MB.
In fact, if you look at some books by J.A. Konrath (links below), who's books are in the range of 250+ pages (much bigger than my SS) with nice book covers that look great on screen, you'll see his file sizes are coming in very low, around 450KB to 700KB. Here Here Here
Since Amazon charges you a $.15/MB "delivery" charge for the 70% royalty option, I want to keep the overall file size down to the lowest it can be while maintaining the appearance and quality of the cover.
In short, what should the resolution and pixel size be to maintain good quality on ALL Kindle devices?
I'm also intending on publishing this story to Nook Press, iBooks, and Kobos. Is there a standard res/pixel size that will encompass all platforms?
Your responses are greatly appreciated, and thank you in advance!
I'm about to publish a short story (approx. 17K words) to Kindle Direct Publishing for the first time, and I'm having trouble figuring out exactly how to properly format the book cover file. I've extensively researched this online (and read KDP's formatting instructions) and am running into a lot of conflicting suggestions. I am looking for responses from people who have first-hand experience publishing books to KDP with successful file formatting results.
The main problem I'm running into is that, according to KDP's instructions, a book cover should be 1563 x 2500 pixels. (As a side-note, this 1563 x 2500 pixels doesn't seem to compute to the standard 6" x 9" cover of a printed book.) When I size the cover to these specs, it's around 4.2MB, even at a 72dpi. When this is added to the size of the .doc file of the story, the overall file size is near 5MB. At 300dpi, it's over 5MB. I'm further confused because when you look at the file sizes on books listed on Amazon, not many, especially short stories, are as big as 5MB.
In fact, if you look at some books by J.A. Konrath (links below), who's books are in the range of 250+ pages (much bigger than my SS) with nice book covers that look great on screen, you'll see his file sizes are coming in very low, around 450KB to 700KB. Here Here Here
Since Amazon charges you a $.15/MB "delivery" charge for the 70% royalty option, I want to keep the overall file size down to the lowest it can be while maintaining the appearance and quality of the cover.
In short, what should the resolution and pixel size be to maintain good quality on ALL Kindle devices?
I'm also intending on publishing this story to Nook Press, iBooks, and Kobos. Is there a standard res/pixel size that will encompass all platforms?
Your responses are greatly appreciated, and thank you in advance!
Best answer: There's not really a standard size that works for all vendors—some care about minimum dimensions, others about maximum file size.
For Amazon and Apple, our house standard is a 2400x3600 jpeg. Neither of them care about file size, but Amazon specifically wants a minimum of 1000px on the longer size, and advises that “for best quality, your image would be 2820 pixels on the shortest side and 4500 pixels on the longest side.” B&N doesn't accept covers larger than 2MB, so we also generate a 1333x2000 jpeg and maybe jack up the compression a bit. Kobo wants covers to be smaller than 5MB, which is often the 3600, but not always.
Note that at 1.5, this is the same aspect that 6"x9" trade paperbacks have, which can be convenient if you intend to also publish via CreateSpace. Kindles have a 1.6 aspect, though, so we're not filling the entire screen.
The Kindle Fire HDX 8.9" has a screen resolution of 2560 x 1600, so if looking good on ALL Kindle devices is your goal, I'd assume that as a minimum size for feeding to KDP.
I've never generated a Kindle book from a .doc—we feed ePubs into KDP for that—but your 17,000 word short story shouldn't be anything like 800K, once converted. The 75,000 word novel I published this morning is a 307K ePub, sans cover, and KindleGen just about doubles the size. If you're looking to shave bytes and your file is any bigger than 200K, you might want to see if Word is dumping buckets of unneeded styling in it (I'll bet it is).
posted by mumkin at 4:39 PM on October 15, 2014
For Amazon and Apple, our house standard is a 2400x3600 jpeg. Neither of them care about file size, but Amazon specifically wants a minimum of 1000px on the longer size, and advises that “for best quality, your image would be 2820 pixels on the shortest side and 4500 pixels on the longest side.” B&N doesn't accept covers larger than 2MB, so we also generate a 1333x2000 jpeg and maybe jack up the compression a bit. Kobo wants covers to be smaller than 5MB, which is often the 3600, but not always.
Note that at 1.5, this is the same aspect that 6"x9" trade paperbacks have, which can be convenient if you intend to also publish via CreateSpace. Kindles have a 1.6 aspect, though, so we're not filling the entire screen.
The Kindle Fire HDX 8.9" has a screen resolution of 2560 x 1600, so if looking good on ALL Kindle devices is your goal, I'd assume that as a minimum size for feeding to KDP.
I've never generated a Kindle book from a .doc—we feed ePubs into KDP for that—but your 17,000 word short story shouldn't be anything like 800K, once converted. The 75,000 word novel I published this morning is a 307K ePub, sans cover, and KindleGen just about doubles the size. If you're looking to shave bytes and your file is any bigger than 200K, you might want to see if Word is dumping buckets of unneeded styling in it (I'll bet it is).
posted by mumkin at 4:39 PM on October 15, 2014
The way you talk about dpi and resolution suggests that you're fiddling with values that you don't understand. Ignore the DPI - the Kindle is going to scale your cover to the size (subject to aspect ratio restrictions) regardless of the dpi.
Do make sure you're saving the cover in a suitably compressed format - I have 2500x1600 images on my machine that are < 1Mb and are perfectly acceptable. JPEG at 85% quality (say) should be fine, or if it's a block colour image then a PNG (which is automatically compressed) might be better if Kindles will display them.
posted by pharm at 3:38 AM on October 16, 2014
Do make sure you're saving the cover in a suitably compressed format - I have 2500x1600 images on my machine that are < 1Mb and are perfectly acceptable. JPEG at 85% quality (say) should be fine, or if it's a block colour image then a PNG (which is automatically compressed) might be better if Kindles will display them.
posted by pharm at 3:38 AM on October 16, 2014
Response by poster: Thank you, everyone! I spent last night and today applying some of the suggestions and am in much better shape!
bcwinters: Yes, I am working with the file as a JPG. I reduced the cover to 80% and that seems to be working well. I used the "Save for Web & Devices" feature. Thanks for the tip.
mumkin: I adjusted the cover to 2560 x 1600 and that works great. Thank you for mentioning the unneeded styling that Word might be dumping into the file. I copy-and-pasted the text into a plain-text file and copy-and-pasted it back into Word, and that cleaned it up well, reducing the file from 450KB to 60KB! I have to go back and restyle the manuscript, but that's not a problem.
pharm: I don't think Kindle will display PNGs (have to check into that for sure). I didn't think I had to worry about dpi and assumed I could set it to 72, but I came across numerous suggestions that advised against a dpi that low, saying you should have a dpi of around 300.
All in all, I still can't get the whole file (story and cover) below 500KB before Amazon's conversion, which will put it somewhere around 1MB, but I'll keep working at it because that still seems large for a 17,000 short story.
Thanks again!
posted by LillyBird at 5:14 PM on October 16, 2014
bcwinters: Yes, I am working with the file as a JPG. I reduced the cover to 80% and that seems to be working well. I used the "Save for Web & Devices" feature. Thanks for the tip.
mumkin: I adjusted the cover to 2560 x 1600 and that works great. Thank you for mentioning the unneeded styling that Word might be dumping into the file. I copy-and-pasted the text into a plain-text file and copy-and-pasted it back into Word, and that cleaned it up well, reducing the file from 450KB to 60KB! I have to go back and restyle the manuscript, but that's not a problem.
pharm: I don't think Kindle will display PNGs (have to check into that for sure). I didn't think I had to worry about dpi and assumed I could set it to 72, but I came across numerous suggestions that advised against a dpi that low, saying you should have a dpi of around 300.
All in all, I still can't get the whole file (story and cover) below 500KB before Amazon's conversion, which will put it somewhere around 1MB, but I'll keep working at it because that still seems large for a 17,000 short story.
Thanks again!
posted by LillyBird at 5:14 PM on October 16, 2014
Best answer: If you want it any smaller, you're probably going to have to start using the command line tools to convert directly to a Kindle .mobi file directly from a suitable html file + metadata. Download Kindlegen from Amazon and have a play around.
posted by pharm at 7:09 AM on October 17, 2014
posted by pharm at 7:09 AM on October 17, 2014
Amazon says that KDP supports GIF, JPEG, PNG and BMP as image formats -https://kdp.amazon.com/help?topicId=A1B6GKJ79HC7AN - but the wording suggests that Kindles themselves will only display GIF or JPEG.
posted by pharm at 7:17 AM on October 17, 2014
posted by pharm at 7:17 AM on October 17, 2014
Response by poster: Pharm, thank you for checking on the image type. Amazon's wording is a little confusing. I've never used command line tools before, so thank you very much for the suggestion. I'm not sure how effective a novice like me will be, but I'll give it a try.
Overall, reducing the file size of the image is driving me a bit nuts because I can't see how some of these books/short stories are as low as they are. I found one in the 170-range of kb for a 200-something page book with a nice cover. I asked a friend of mine who's a web designer, and he said the file sizes seem to be "impossibly low," but obviously it's being done, so there has to be a way. Thank you for your help! Any other suggestions, I'll take them. And if I find the solution, I'll post for anyone else down the road.
posted by LillyBird at 10:25 PM on October 17, 2014
Overall, reducing the file size of the image is driving me a bit nuts because I can't see how some of these books/short stories are as low as they are. I found one in the 170-range of kb for a 200-something page book with a nice cover. I asked a friend of mine who's a web designer, and he said the file sizes seem to be "impossibly low," but obviously it's being done, so there has to be a way. Thank you for your help! Any other suggestions, I'll take them. And if I find the solution, I'll post for anyone else down the road.
posted by LillyBird at 10:25 PM on October 17, 2014
A cover with plain block colours, using the GIF format will be compressed to a very small file size - GIF compression works really well on areas that are all the same colour whilst preserving the sharp edges on text etc that jpeg tends to choke on.
There's some useful information on generating Kindle mobi files on the mobileread wiki - it's quite a bit more detailed than Amazon's rather sparse documentation!
posted by pharm at 12:16 AM on October 18, 2014
There's some useful information on generating Kindle mobi files on the mobileread wiki - it's quite a bit more detailed than Amazon's rather sparse documentation!
posted by pharm at 12:16 AM on October 18, 2014
Best answer: A few articles that may be helpful in reducing file size: Minimizing Your eBook File Size and Make More Money on Kindle by Reducing Your .mobi File Size.
One notable point is that the cover embedded in the ebook does not count toward the Kindle delivery charge. Also notable is that the physical file size of the MOBI eBook is not what Amazon will use to calculate the delivery fee.
posted by alicat at 10:49 PM on October 18, 2014
One notable point is that the cover embedded in the ebook does not count toward the Kindle delivery charge. Also notable is that the physical file size of the MOBI eBook is not what Amazon will use to calculate the delivery fee.
posted by alicat at 10:49 PM on October 18, 2014
Response by poster: alicat: You're AWESOME! I have scoured the Internet and never came up with this info (hopefully it is hard to find or I'm a terrible researcher!). Thank you so much! And your links are especially helpful!
pharm: mobileread wiki is a trove I'm going to have to start going through. At first glance, though, it IS more detailed and will be extremely helpful. Thank you!
As for your GIF suggestion. Perhaps I don't know how to properly work with GIF files (which I may not), but when I change my cover from JPG to GIF, the file size actually increases. I'm not sure how much it matters with my cover because it's a photo illustration. And although it's not very busy, it doesn't have a solid color background. But I'll try tweaking again in a GIF format.
Thank you, again! You all have been great!!!
posted by LillyBird at 2:52 PM on October 19, 2014 [1 favorite]
pharm: mobileread wiki is a trove I'm going to have to start going through. At first glance, though, it IS more detailed and will be extremely helpful. Thank you!
As for your GIF suggestion. Perhaps I don't know how to properly work with GIF files (which I may not), but when I change my cover from JPG to GIF, the file size actually increases. I'm not sure how much it matters with my cover because it's a photo illustration. And although it's not very busy, it doesn't have a solid color background. But I'll try tweaking again in a GIF format.
Thank you, again! You all have been great!!!
posted by LillyBird at 2:52 PM on October 19, 2014 [1 favorite]
You're welcome, LillyBird! Credit where it's due - I got these links from another author in the Instant Bestseller Facebook group (run by Tim Grahl of "Your First 1000 Copies"). I'm about to format my own ebook this week so it's timely for me too. Good luck with the publication!
posted by alicat at 10:28 PM on October 19, 2014
posted by alicat at 10:28 PM on October 19, 2014
No problem Lilybird - glad to be of help.
On the GIF vs JPEG thing: JPEGs are great for images like photographs of real objects or paintings, whereas GIFs are good for images with large blocks of the same colour. JPEGs tend to leave lots of weird visual artifacts on images with sharp edges between blocks of different colour / brightness (eg around text) unless you turn the quality up very high which makes the filesize much bigger.
It's really just a matter of trying them out & seeing which gives the best visual quality for the filesize you want to target. (If GIF compression is turned off then that will usually be the largest file size though.) A GIF will always give the best visual quality, because it doesn't throw any information away (unless you use more advanced techniques like reducing the colour space to fewer individual colours before converting the image to a GIF) and so is usually larger. If you happen to have a file that GIF compression does well on (which means large blocks of the same colour) then a GIF might be smaller.
JPEGs throw information away, which is why they're smaller - usually it's information that you don't really need, but in some cases it results in really obnoxious visual changes to the image, especially at stronger compression levels. Text is a particular bugbear for JPEGs because it requires lots of sharp edges in the image which the JPEG format can't encode efficiently.
Best of luck with your eBook!
posted by pharm at 5:50 AM on October 20, 2014
On the GIF vs JPEG thing: JPEGs are great for images like photographs of real objects or paintings, whereas GIFs are good for images with large blocks of the same colour. JPEGs tend to leave lots of weird visual artifacts on images with sharp edges between blocks of different colour / brightness (eg around text) unless you turn the quality up very high which makes the filesize much bigger.
It's really just a matter of trying them out & seeing which gives the best visual quality for the filesize you want to target. (If GIF compression is turned off then that will usually be the largest file size though.) A GIF will always give the best visual quality, because it doesn't throw any information away (unless you use more advanced techniques like reducing the colour space to fewer individual colours before converting the image to a GIF) and so is usually larger. If you happen to have a file that GIF compression does well on (which means large blocks of the same colour) then a GIF might be smaller.
JPEGs throw information away, which is why they're smaller - usually it's information that you don't really need, but in some cases it results in really obnoxious visual changes to the image, especially at stronger compression levels. Text is a particular bugbear for JPEGs because it requires lots of sharp edges in the image which the JPEG format can't encode efficiently.
Best of luck with your eBook!
posted by pharm at 5:50 AM on October 20, 2014
Response by poster: alicat: good luck with your publication, too! I hope it does great!
pharm: One more time, thank you! You gave me a lot of info I didn't know about both those formats, especially re: blocks of color and sharp edges. This info will undoubtedly come in handy many times over now that I am doing ebooks. I've only worked with JPEGs for print on web presses, where everything needs to be big. This ebook stuff is completely opposite what I'm used to because I'm totally unaccustomed to making images smaller. You've been a great help again. Thank you so much!
posted by LillyBird at 10:06 PM on October 20, 2014
pharm: One more time, thank you! You gave me a lot of info I didn't know about both those formats, especially re: blocks of color and sharp edges. This info will undoubtedly come in handy many times over now that I am doing ebooks. I've only worked with JPEGs for print on web presses, where everything needs to be big. This ebook stuff is completely opposite what I'm used to because I'm totally unaccustomed to making images smaller. You've been a great help again. Thank you so much!
posted by LillyBird at 10:06 PM on October 20, 2014
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Also, are you saving your cover image as a JPG? Have you tried different compression settings? With dimensions as large as Amazon recommends, you should be able to do a fair amount of compression without it being noticeable—maybe 30-40% or so (or “60-70% quality” if your graphics editor lists the percentage that way). If you’re using Photoshop you can preview the compression percentage (along with the resulting file size) as you fiddle with it if you use the “Save for Web & Devices” feature.
posted by bcwinters at 4:16 PM on October 15, 2014