Free Image Tools

The terms DPI (dots per inch) and PPI (pixels per inch) are frequently used interchangeably but refer to distinct concepts. PPI is a property of a digital image: the number of pixels packed into each linear inch of the image at its intended display or print size. It describes the image's data density. DPI is technically a property of the output device - A printer's resolution in physical ink dots per inch. A 600 DPI inkjet printer places 600 ink dots in every inch of paper; the image fed to it should ideally be 300 PPI so that each pixel receives two ink dots for optimal rendering. In practice, most people use DPI to mean PPI when discussing digital images, and the DPI Calculator handles both interpretations.

The standard resolution benchmarks for different output contexts are well established in the printing industry. 72 PPI is the historical screen resolution (originally the Macintosh standard) and remains the baseline for images intended for screen-only display - Though modern Retina and HiDPI screens have more than doubled this. 150 PPI is adequate for standard inkjet printing where the viewing distance is greater than arm's length - Posters, banners, and large-format signage. 300 PPI is the professional print standard for offset and commercial printing, photo books, packaging, and anything viewed at close range. 600 PPI and above is reserved for fine art giclée printing on canvas or fine cotton rag paper, where archival standards and close-inspection printing demand maximum pixel density.

The calculation is straightforward: divide the pixel dimension by the desired DPI to get the maximum print size in inches. A 6000×4000 pixel photograph - Typical of a 24-megapixel camera - Can print at a maximum of 20×13.3 inches at 300 DPI (6000 ÷ 300 = 20). The same file at 150 DPI yields a 40×26.7 inch print - Suitable for a trade show banner. Modern cameras from 2020 onward produce 24–61 megapixel files; a 61-megapixel medium-format capture (9504×7984 pixels) can print at a monumental 31.7×26.6 inches at full 300 DPI quality. Use the DPI Calculator to find your exact maximum print dimensions - Enter your image's pixel dimensions and target DPI to see the result immediately.

An important caveat: the 300 DPI rule applies to the final printed size, not the display size on screen. Web images at 72 PPI do not need to be "upgraded" to 300 PPI for online use - Screen resolution is measured in total pixels, not density. A 1920×1080 pixel image displays correctly on a 1080p monitor regardless of its embedded PPI value. The PPI metadata embedded in an image file is an advisory hint for print applications, not a constraint on on-screen display quality.

EXIF (Exchangeable Image File Format) is a metadata standard embedded by digital cameras and smartphones into JPEG, TIFF, and raw image files at the moment of capture. A typical EXIF block contains several dozen fields: camera make and model (e.g., Sony ILCE-7M4), lens identification (e.g., FE 50mm F1.2 GM), exposure triangle values (ISO sensitivity, shutter speed as a fraction, aperture as an f-number), focal length in mm and 35mm equivalent, white balance mode, flash status, orientation flag (whether the camera was rotated when the photo was taken), and original date/time with sub-second precision. The Image Info tool displays all available EXIF fields in a structured, readable layout.

The GPS sub-IFD within EXIF stores latitude, longitude, altitude, and GPS timestamp when location services are enabled on the capture device. This has significant privacy implications: a photograph shared online with GPS data intact reveals the exact location where it was taken - Including private homes, workplaces, and frequented locations. The precision is typically within 5–10 meters. Journalists, activists, crime victims, and anyone concerned about location privacy should strip EXIF GPS data before sharing photos publicly. Use Image Info to check whether your photo contains GPS coordinates before uploading it anywhere.

IPTC (International Press Telecommunications Council) fields are a separate metadata standard layered alongside EXIF, primarily used by professional photographers, news agencies, and stock photo libraries. IPTC fields include: copyright notice and rights statement, creator/photographer name, caption and description, keywords and category tags, city/country of origin, and usage instructions. These fields allow images to carry their own licensing and attribution information through distribution chains. Many photo editing applications (Lightroom, Capture One, Bridge) write IPTC fields as part of standard cataloging workflows.

ICC color profiles embedded in image files specify the color space the image was created in. The three most common are: sRGB - The universal default for web and consumer devices, covering approximately 35% of the visible spectrum; Adobe RGB (1998) - A wider gamut covering ~50% of the visible spectrum, preferred by photographers and designers working in print; and Display P3 - Apple's wide-color standard used on modern iPhones, iPads, and Mac displays, covering ~45% of the visible spectrum. When an image with an Adobe RGB or P3 profile is displayed on a device or application that doesn't honor the profile, colors appear muted or shifted. Check your images' embedded profiles with Image Info to diagnose color reproduction issues.

Color relationships in photography and design are governed by a set of well-studied harmonic structures. Complementary colors sit directly opposite each other on the color wheel - Blue and orange, red and green, purple and yellow - And create high-contrast, vibrant pairings that draw the eye. Analogous palettes group colors adjacent on the wheel (e.g., red, red-orange, orange) for harmonious, low-tension compositions common in landscape and nature photography. Triadic schemes use three colors equally spaced at 120° intervals, producing energetic but balanced combinations. Monochromatic palettes vary only lightness and saturation within a single hue, creating refined, cohesive visual systems widely used in minimal brand identities.

Photographs make fertile starting points for brand palette extraction: a hero image's dominant and accent colors can seed an entire design system. A coastal photograph might yield a primary navy blue, a secondary warm sand, and an accent coral - A palette that carries the brand's visual identity across web, print, and packaging with inherent coherence. The Color Palette tool extracts dominant colors from uploaded images and generates harmonically related variants in all four relationship types.

Color notation varies by use context. HEX (#3A86FF) is the standard for HTML and CSS web development. RGB (rgb(58, 134, 255)) is used in CSS, JavaScript canvas operations, and design tool APIs. HSL (hsl(216, 100%, 61%)) represents hue, saturation, and lightness - More intuitive for making incremental adjustments (lighten by 10%, desaturate by 20%) than raw RGB values. CMYK (C:77 M:47 Y:0 K:0) is required for print workflows where the output device mixes physical pigments. CSS custom properties allow all these values to be defined once as design tokens (--color-primary: #3A86FF) and referenced throughout a stylesheet, enabling one-line global rebranding. The Color Palette generator exports in all these formats simultaneously.