DPI stands for dots per inch, and for a printed book it is the number that decides whether a picture looks sharp or blurry. A printer needs enough pixels in every inch of the picture to hide the individual dots, and for books the usual target is 300 pixels per inch. An image with fewer pixels than the printed size needs is enlarged by the software, and enlarging does not add detail. It spreads the same pixels across a larger area, and the result looks soft or blocky.
Free tool · Image DPI Checker
Image DPI Checker that tells you whether an image is sharp enough to print
The image dpi checker reads the pixel size of your image, or takes the pixels that you type, and works out the effective DPI at the size you plan to print, then tells you whether it is good for print, acceptable, soft or too low, and lists the largest print size at 300, 240, 200 and 150 DPI. The file is read in your browser and never uploaded, and the tool is free for authors, illustrators and cover designers.
Use the free tool
The image dpi checker is free to use, with no account and nothing uploaded.
- Pixel size and effective DPI
- Max print size at 300 DPI
- Files are read on your device
Key facts
- FreeNo cost, no account and no usage limit on the image dpi checker
- In your browserNothing that you type or paste into the image dpi checker is uploaded
- SecondsTypical time from opening the image dpi checker to a result
Free tool
Image DPI checker
Choose an image to see its pixel size, or enter the pixels yourself, and check the effective DPI at the size you plan to print it. The file is read in your browser and never uploaded.
The image dpi checker needs JavaScript, and it works in your browser without sending anything that you enter to a server.
Overview
What the image dpi checker does and why it helps
The number that matters is the effective DPI, which is the number of pixels in the image divided by the size at which it will print. A photograph of 1,800 by 2,700 pixels printed at 6 by 9 inches has an effective DPI of 300, which is good. The same photograph printed at 12 by 18 inches has an effective DPI of 150, which will look soft. The density tag that some files carry, such as 72 DPI, is only a label and does not change the pixels, so the tool ignores it and tells you what counts.
You can choose an image file, and the tool reads its pixel size in your browser, or you can type the pixel width and height yourself. Then you enter the printed width in inches, and optionally the height, and the tool gives you the effective DPI, a plain verdict and a table of the largest size that each quality level allows. It also notes any density tag that it finds in a JPEG, so that you can see the label and the reality side by side.
The image DPI checker works out the effective resolution of a picture at the size you plan to print it, so a soft image does not slip into the final file. You will not pay for this free image dpi checker; it exists to save you a spreadsheet and some guesswork. You can use the image dpi checker online in any modern browser, with nothing to install. The wording and defaults suit an image dpi checker for authors, not general business users. Indie writers can rely on it as an image dpi checker for self-published books. Amazon authors can use it as an image dpi checker for KDP with no changes. As a image dpi checker no sign up page, it asks for no email and sets no account. We cannot say what the best image dpi checker is for everyone, but we have made this one show its working so you can trust the answer.
Authors often need an image DPI checker online tool for a single cover or interior picture. This image resolution DPI checker reads the pixel size, so it is a quick DPI checker for image files. Searches for an image DPI checker TIFF or image DPI checker PDF usually come from print files, and the same rule applies: what matters is pixels against printed inches. It is also a free online image DPI checker that works on any file you can open in your browser.
How to use it
How to use the image dpi checker, step by step
Choose your image or type its size
Select a file from your device, or enter the width and height in pixels. Files are read in your browser and are not uploaded, so unfinished artwork stays private on your machine.
Enter the print size
Type the width you plan to print, in inches or millimetres. The tool uses it with the pixel width to work out the effective resolution at that size.
Read the effective DPI
The tool divides pixels by inches to give the dots per inch the image will have in print. A higher number means finer detail and sharper output.
Check the verdict
The tool says whether the result is good for print, acceptable, soft or too low. Use the verdict as a guide to whether the image needs replacing.
Read the size table
The tool lists the largest print size at 300, 240, 200 and 150 DPI. It shows how far the image can be enlarged before quality drops.
Decide what to do
If the result is too low, find a larger source, print smaller or accept softer output. Do not rely on enlarging in software, because it cannot add real detail.
How the image dpi checker works
Pixels divided by inches
Choose an image and the tool reads its width and height in pixels. Enter the size you plan to print, and it divides the pixels by the inches to give the effective DPI. For a TIFF or PDF, which browsers cannot read, you can type the pixel size instead.
It then judges the result against common thresholds: 300 DPI or more is the usual target for books, 240 to 300 is acceptable, 150 to 240 will look soft and below 150 will look blurry. It also lists the largest print size that you can reach at 300, 240, 200 and 150 DPI.
The tool also reads the density tag that some JPEG and PNG files carry and shows it, with a reminder that it is only a label. Everything happens in your browser, so a private cover or a draft image never leaves your computer.
- Reads pixels from JPG, PNG, WebP and GIF files
- Largest print size at four quality levels
- Reads any embedded density tag
Method
How the image dpi checker works out its answer
Effective DPI
The pixel width is divided by the printed width in inches, and the pixel height by the printed height. The smaller of the two results is reported, since the weakest direction decides the quality.
The verdict
At 300 DPI or more the image is good for print. From 240 to 300 DPI it is acceptable for most books. From 150 to 240 DPI it will look soft on a cover and an effort should be made to find a larger source. Below 150 DPI it will look blurry in print.
The size table
For each of 300, 240, 200 and 150 DPI, the tool divides the pixel size by the DPI and shows the largest printed size in inches and millimetres at that quality.
The density tag
A JPEG can carry a density label such as 72 or 300 DPI. It does not change how many pixels the picture has, and the tool shows it only for information.
Tips
Getting the most from the image dpi checker
Ask for the largest file
Source images are usually larger than web copies. Request the original from the photographer, the stock library or the designer. The image dpi checker is free and instant, so it is worth running again whenever your book changes.
Aim for 300 DPI
It is the common standard for print and a safe target for photographs and covers. Lower values may be acceptable for large, distant prints.
Accept lower for large prints
Posters and banners are viewed from a distance, and 150 DPI is often enough there. Book pages are held close, so aim higher.
Need it done for you?
When the image dpi checker is not enough
The checker tells you whether your images are sharp enough. These services fix low-resolution cover files and build picture-heavy interiors that print the way they look.
Fix Book Cover Resolution Errors
If a printer has flagged your cover for low resolution, a specialist rebuilds the file with the right pixel size and checks it against the printer's template.
See the service →Full Color Book Formatting
A full-colour interior is prepared with every image at the right resolution and colour mode, so that photographs and illustrations print crisply.
See the service →Illustrated Book Formatting
Illustrated books need careful image placement, resolution and bleed, and a formatter lays out every spread and tests the file for print.
See the service →Before and after
Before and after using the image dpi checker
The same book, first printed with images that looked fine on screen and then checked for effective DPI before print.
123Before
- 1A cover image that prints soft
- 2A web photograph used on a full page
- 3A file labelled 300 DPI that is really small
123After
- 1Artwork with enough pixels for the print size
- 2Images matched to the size they print at
- 3A real DPI figure, not a label
- 3problems found in the first review
- 3fixes checked in the final review
- 1named specialist owning every fix
- Fixedprice confirmed in the calculator before you order
Sharp print
Every image has enough pixels for the size it prints at, so edges are crisp and photographs look clean.
Fewer rejections
A printer's check passes first time, because low-resolution artwork is found and replaced before upload.
Confident cropping
You know how far you can crop a picture before it drops below the quality you need.
Client reviews
What authors say about our image resolution check service
Verified reviews from authors who asked a specialist to handle the image resolution check after using the image dpi checker.
My YA novel needed to reach both English-language and Japanese readers. The multi-region distribution setup was handled correctly across all required platforms. International sales have exceeded my expectations.
Good publishing support overall. The KDP metadata setup was thorough. One category selection needed updating after initial launch but it was corrected promptly. The book is performing well in its target categories.
Getting historical fiction placed in the right categories on Amazon and IngramSpark required strategic metadata. The team understood the genre classification and the book reached the right readers from the first week.
My cookbook needed to be set up across multiple platforms simultaneously. The publishing support team handled every submission — KDP, IngramSpark, and Apple Books — with different requirements for each. Flawlessly executed.
Navigating IngramSpark's requirements for the first time felt overwhelming. The upload assistance handled everything — metadata, pricing setup, distribution channels. My children's book reached bookstores within two weeks.
The formatting error fix service saved my launch. My original formatter had made margin errors causing repeated rejection. Book Formatting Experts identified and fixed every issue within 48 hours. My launch was back on schedule.
Good support throughout the KDP upload process. The metadata setup and category selection were explained clearly. One pricing setting needed adjustment after initial setup but it was corrected quickly.
My KDP file was rejected with a technical error message I could not understand. Book Formatting Experts diagnosed the problem immediately — a bleed issue on three pages — and corrected it the same day. Approved first time.
The publishing readiness review identified four issues in my manuscript that would have caused rejection. Each was clearly explained and quickly resolved. My book launched without any technical complications.
As a first-time author, the technical side of self-publishing was genuinely daunting. The consultation covered every decision — platform choice, pricing strategy, metadata, and distribution. I launched with genuine confidence.
My EPUB was rejected twice by Apple Books before I found Book Formatting Experts. They identified the metadata errors, rebuilt the file properly, and the new version passed immediately. Wish I had contacted them first.
Solid formatting work. The chapter headers and page numbers were all clean and the file passed IngramSpark first time. Communication was good throughout. Minor revision was turned around same day.
My nonfiction cover needed to convey authority and accessibility at the same time. The design achieves both. The colour palette and typography feel credible and professional without being intimidating.
The citation formatting, chapter opening pages, and bibliography were all handled precisely. For a scholarly publication, these details matter enormously. The finished book looks authoritative and professional.
The website feels faith-centred without being off-putting to first-time visitors. The devotional resource section, speaking ministry page, and book store all reflect the purpose of my work clearly and respectfully.
Historical fiction requires a formal, unhurried typography that feels appropriate to the period. The specialist understood this without me having to explain it at length. The result is elegant and exactly right.
My thriller needed a fast, clean layout with short chapters that kept the pacing tight on the page. The formatting reinforced the reading rhythm I had built into the manuscript. Exactly right.
My thriller needed a cover that was unsettling without being gratuitous. The designer found exactly the right tone. The typography treatment adds to the unease in a subtle, effective way.
More free tools
More free tools to use with the image dpi checker
Each of these tools is free, runs in your browser and works well alongside the image dpi checker.
Color Converter For Print
With your image resolution check, free color converter for print that works in your browser, plus a done-for-you cover colour check service.
Open the tool →Book Cover Thumbnail Preview
For your image resolution check, free book cover thumbnail preview that works in your browser, plus a done-for-you cover thumbnail review service.
Open the tool →Ebook File Size Calculator
Free ebook file size calculator that works in your browser, plus a done-for-you ebook file optimisation service.
Open the tool →Spine Width Calculator
Free spine width calculator that works in your browser, plus a done-for-you spine measurement check service in this image resolution check order.
Open the tool →Typography Unit Converter
For a image resolution check, free typography unit converter that works in your browser, plus a done-for-you typography setup service.
Open the tool →Book Font Pairing Tool
For your image resolution check, free book font pairing tool that works in your browser, plus a done-for-you typography pairing review service.
Open the tool →FAQ
Image DPI Checker: questions answered
These are the questions authors ask most about the image dpi checker, including accuracy, privacy and what to do next. If your question about the image resolution check is missing, request a quote and a specialist will reply.
What is an image dpi checker?
It is a tool that works out the effective DPI of an image at the size you plan to print it, so that you can tell whether the picture has enough pixels to look sharp.
What DPI do I need for a book?
For print, the usual target is 300 DPI at the final size. Between 240 and 300 is acceptable for most books, and below 150 will look blurry.
What is effective DPI?
It is the number of pixels in the image divided by the printed size in inches. It is the figure that decides print quality, whatever the file's own label says.
Does 72 DPI mean the image is too small?
Not by itself. The 72 is a label, and an image with many pixels can be labelled 72. What matters is the pixel size compared with the print size.
Can I increase the DPI of a small image?
You can resample it, but no detail is added, so it will still look soft. A larger original is the real fix.
Does the image dpi checker keep anything that I enter?
No. The image dpi checker works in your browser, so what you enter stays on your device and is never saved.
Which file types does it read?
It reads common image types such as JPG, PNG, WebP and GIF, and you can also enter pixel sizes by hand without any file.
What if I do not have the image file?
Type the pixel width and height, and the tool will give the same results.
How big can I print a 1,000 pixel wide image?
At 300 DPI, about 3.3 inches wide. At 150 DPI, it can stretch to about 6.7 inches, though it will look soft.
Do I need 300 DPI for a cover?
Yes, in most cases, at the full wrap size including the bleed. A soft cover image is easy to see on a printed book.
What about images inside an ebook?
Ebook screens need fewer pixels, and the file size matters too, so the ebook file size calculator is useful as well.
Is the image dpi checker free?
Yes, the image dpi checker costs nothing, needs no account and puts no limit on how many images you check.
What is the difference between DPI and PPI?
Strictly speaking, PPI counts the pixels in a digital file while DPI counts the ink dots a press physically puts down. In everyday publishing conversation the two words are used interchangeably to mean the same thing, and printers who ask for 300 DPI artwork mean 300 pixels per printed inch.
My image says 72 DPI in Photoshop. Is it unusable?
Not necessarily. The tag stored in a file is only metadata and says nothing about the pixel count, which is what actually matters. A photograph tagged 72 can still be five thousand pixels wide and print beautifully. Check the pixel dimensions, which is exactly what this tool reads.
How does an image dpi checker work?
Enter the pixel dimensions and the print size, and it divides one by the other to show the effective DPI, with a clear pass or warning.
Work with a specialist
Turn what you learn from the image dpi checker into a finished book
The image dpi checker costs nothing, and so does asking what a specialist would do with your book. When the image dpi checker has done its part and you want finished files, a fixed price and one named person who owns the job, we are ready to start.