Guide · updated October 2026
How to increase the DPI of an image
Before picking a menu path, check whether the file already contains enough pixels. If it does, you are changing a label. If it does not, you are enlarging the image, with real trade-offs.
Need the short version?
Drop a file, set the target, and read the verdict before you decide between tag-only and resampling.
01
Diagnose the file
Start with three numbers: embedded DPI, pixel dimensions, print size.
Check the embedded DPI first. A DPI checker shows every resolution block, which matters because a JPEG can hold one value in JFIF and another in EXIF. Next, note the pixel dimensions. They set the ceiling on print quality. Finally, decide the physical size you need, because “enough DPI” only means something relative to paper.
Divide the pixel width by the print width in inches. The result is the effective DPI at that size. A 3000 px wide file printed 10 inches wide resolves to 300 DPI. The same file printed 20 inches wide resolves to 150 DPI. The tag can say anything; this division is what the paper receives.
| Print size | Pixels for a clean 300 DPI print |
|---|---|
| 4 × 6 in | 1,200 × 1,800 px |
| 5 × 7 in | 1,500 × 2,100 px |
| 8 × 10 in | 2,400 × 3,000 px |
| A4 | 2,481 × 3,508 px |
| 11 × 14 in | 3,300 × 4,200 px |
02
Choose the operation
Only the tag edit can be lossless.
The pixels are enough
The file resolves at 300 DPI or close to it for your print size. Change the resolution tag and stop. This is lossless in the useful sense: the compressed pixel data is copied byte for byte, no new JPEG compression is applied, and EXIF survives.
The pixels are short, and the print is small
A 1200 × 900 px image cannot fill an 8 × 10 sheet cleanly, but it is fine at 4 × 3 inches. Change the tag and print at the size the pixels support. The print is sharp at that size, while an enlargement of the same file would be soft.
The pixels are short, and the size is fixed
Now you need new pixels. Resampling estimates them from their neighbours. The result can be acceptable for a poster, a canvas or a soft-focus background, but it is not the same image at higher fidelity. Decide whether that trade is acceptable before you start, because the output is re-encoded and metadata is lost.
03
Change the tag
Four ways to change the tag.
Browser converter (lossless)
The converter on this page edits JPEG, PNG, BMP and TIFF resolution blocks directly. It writes both JFIF and EXIF in a JPEG, inserts a pHYs chunk in a PNG when needed, and reads the saved bytes back before the download unlocks. Nothing is uploaded.
macOS Preview
Open the image, choose Tools → Adjust Size, and set the resolution. When “Resample image” is off, the pixel dimensions stay fixed and only the print density changes. Turn it on and Preview will create new pixels instead. Save a copy and re-check the dimensions, because the dialog makes it easy to change the wrong setting.
ExifTool (command line, in-place)
ExifTool edits metadata without touching the compressed image data. This sets both EXIF resolution and the JFIF density that many older apps read:
exiftool -XResolution=300 -YResolution=300 -ResolutionUnit=inches \
-JFIF:XResolution=300 -JFIF:YResolution=300 -JFIF:ResolutionUnit=1 \
photo.jpgsips (macOS, rewrites the file)
sips -s dpiWidth 300 -s dpiHeight 300 in.jpg --out out.jpg sets the tag, but sips writes a new file through ImageIO rather than patching bytes in place. Keep the original and check that the pixel dimensions did not move.
04
Resample the pixels
Resample once, at the final size.
Photoshop
Image → Image Size. Switch Resample on, enter the final pixel dimensions or the print size at 300 DPI, and choose an enlargement method. Bicubic Smoother is the traditional choice for upscaling; Preserve Details handles noisy photographs with more control. Resampling in several 20% steps is an old trick that mostly adds softness.
Affinity Photo and GIMP
Affinity uses Document → Resize Document with a resample switch. GIMP separates the two operations: Image → Print Size sets resolution without changing pixels, while Image → Scale Image changes the pixel grid. Use Scale Image for enlargement, then set the print resolution.
ImageMagick
magick in.jpg -resample 300 -quality 95 out.jpg resamples to 300 DPI while keeping the physical size. By contrast, -density 300 -units PixelsPerInch only writes metadata and re-encodes the file at its existing pixel size. The two flags are easy to confuse, and only one of them adds pixels.
A practical ceiling: enlargements beyond about 2× start to look synthetic on detailed subjects. Fabric, foliage, hair and small text are the first things to turn to mush. Plain backgrounds, skies and soft portraits tolerate more.
05
AI upscaling, when it is defensible
Where upscaling helps, and where it changes the evidence.
Neural upscalers can reconstruct plausible texture in a way that bicubic interpolation cannot. For a personal print, a product mock-up or a poster of a favourite photo, the result can be genuinely useful. The output is still synthesised. Faces can drift, text can turn into convincing nonsense, and fine patterns can acquire structures that were never in the original.
For documentary, scientific, legal or journalistic images, enlarging with a model changes the evidence. If an AI-enlarged file is submitted anywhere that expects a photograph, disclose the processing. The same rule applies to a resampled file that has been sharpened heavily: it is an interpretation of the capture, not the capture itself.
06
Do it in the browser
Tag-only for the metadata fix; resample when the print size cannot change.
Batch converter
No files yet
Tag-only mode is the default. It changes every resolution block and leaves the pixels alone. Switch to resample only when the print size has to stay the same.
Drop images to set their DPI
JPEG · PNG · BMP · TIFF · up to 30 files · 100 MB each
Nothing is uploaded. Metadata is read and rewritten inside this tab.
07
Verify, and avoid the usual traps
A five-minute check prevents most reprints.
- Screenshots are not enlargements. Zooming a photo on screen and taking a screenshot records the display, not the original detail. The new file is larger and softer.
- Renaming does not convert. Changing
.jpgto.pngchanges the label, not the encoding. Use a real conversion if a form demands PNG, and expect re-encoding loss from JPEG. - Upload sites see your files. Many free converters process on a server. For client work, identity documents or unpublished photographs, prefer a local tool and check the network panel if you are unsure.
- Do not resample twice. Each pass estimates from the last estimate. Start from the largest original and make one enlargement at the final size.
- 72 DPI is not a defect. It is a common export default. Judge the file by pixels against the print size, not by the number in the tag.
- Check the output, not the settings. Re-open the saved file, confirm 300 DPI in every block, and confirm the pixel dimensions. Editors and upload forms silently re-tag files more often than you would expect.
Questions people ask
Common questions about raising DPI.
How do I increase DPI without changing the pixels?
Rewrite the resolution metadata. In this browser tool, choose tag-only mode and a target value; on the command line, ExifTool can set XResolution, YResolution and ResolutionUnit in place. The pixel grid and the compressed image data are left untouched.
Can I increase DPI in Windows without extra software?
Windows does not include a working tag editor. The Details tab in file Properties can display horizontal and vertical resolution but not change it. Paint and Photos resize pixels rather than editing resolution, and saving through them can strip metadata. A browser tool or ExifTool is the practical route.
Does increasing DPI increase image resolution?
Not by itself. DPI is a print instruction; resolution in the useful sense is the pixel count. Raising the tag from 72 to 300 DPI leaves the pixel count unchanged and shrinks the printed size. Only resampling adds pixels, and those new pixels are interpolated rather than recorded.
How do I increase DPI in Photoshop?
Open Image → Image Size. Turn off Resample to change the resolution while keeping the pixel dimensions, or turn it on to add pixels for a larger print. For enlargements, choose Bicubic Smoother or Preserve Details. Save with metadata intact, because Export As and some web presets strip it.
Is 300 DPI always required for printing?
No. Hand-held photo prints usually benefit from 300 DPI. Posters and banners are viewed from further away and often print at 100 to 150 DPI. Line art and small text may need 600 DPI. The right number depends on the medium and the viewing distance.
Can I increase the DPI of a PDF?
PDF resolution is applied at render time and can differ from page to page. Changing it is a PDF rendering or export task, not a single tag edit. This site does not process PDFs yet.
Why does my photo still look blurry after increasing DPI?
Because the pixels were already too few for the intended print size. A tag change only alters the density at which those pixels are placed. Resampling smooths the enlargement but cannot restore detail that the camera or the export discarded.