Grayscale Image – Black and White Converter

Drop your pictures on the box above and each one becomes a grayscale image in a moment, with a live before-and-after preview. Pick a preset or choose a style yourself: smooth Grayscale, crisp Black & white made of pure black and white pixels, or Colour pop, where one colour stays and everything else goes gray. When it looks right, press the button and download one file, or a whole batch in one ZIP.

All of it happens in your browser. Your photos are opened, converted and saved on your own device, and nothing is uploaded. JPG, PNG, WebP and HEIC photos from iPhones work, and most browsers also open GIF, BMP and AVIF. The result keeps the full resolution of the original, unless you set a print or engraving size yourself.

This grayscale image converter offers eight choices in the gray method menu, because there is more than one right way to turn colour into gray. Each one decides how much the red, green and blue of a pixel count towards its brightness.

Natural (luminance, Rec. 709) is the default. It weighs green most, red less and blue least, about 72%, 21% and 7%, much as our eyes judge brightness, so the gray version looks as bright as the colour one. Classic TV (Rec. 601) uses the older television weights of about 30%, 59% and 11%; reds come out a little brighter, and many older programs use it.

Average of R, G, B treats all three colours the same, which can make blue skies and green leaves look too light. Lightness (desaturate) takes the middle between the strongest and weakest colour of each pixel, a soft and flat result. Red channel (dramatic skies) uses only red: blue skies turn dark and skin looks smooth, like a red filter on black and white film. Green channel and Blue channel do the same for the other colours; blue shows haze and freckles more strongly.

Custom mix gives you three sliders for the share of R, G and B, starting at 30, 59 and 11 percent. The shares are balanced automatically, so the picture keeps its overall brightness whatever numbers you choose. Try more red to lighten skin and darken skies, or more green to bring out leaves and grass.

Making a grayscale image online free takes three taps here, with no account, no email address and no app to install. There is no watermark on the result, no daily limit and no trial that ends after a few pictures.

It can be free because your own device does the work. Turning colour into gray is a light job for any phone or computer, so there is no server time to pay for and no queue to wait in. Once the page has loaded, each picture is ready in a moment, even on a slow connection.

For a bulk grayscale image online job, select many files at once or drop a whole pile on the box: up to 200 pictures go into one batch. The same settings are used for every picture, and the preview shows the first one, so check that one carefully before you start.

When you press the button, the pictures are converted one after another at full resolution. The list shows the pixel size and file size of each result, and Download all (ZIP) saves every file in one archive named grayscale-images.zip. Single files can be saved from the list as well.

If you change a setting afterwards, the results are cleared and the button is ready again, so you can try another look on the same batch without adding the files a second time. For very large photos or big batches, a computer is more comfortable than a phone, because it has more memory.

People often say black and white when they mean gray, but they are two different things. A grayscale image keeps up to 256 shades from black to white, so a portrait still shows soft skin tones and smooth shadows. A true black and white picture, also called 1-bit or bitmap, has only two values per pixel: black or white, nothing in between.

To go from a grayscale image to black and white, every pixel is compared with a threshold. Pixels lighter than the threshold become white, darker ones become black. With Automatic threshold ticked, the tool uses Otsu's method: it looks at all the gray levels in the picture and picks the one that best splits it into a dark part and a light part. The hint under the preview tells you which threshold was used.

Untick Automatic threshold to set the Threshold slider yourself, from 1 to 254. Lower values make more of the picture white and thin out text; higher values make more of it black and thicken lines. For scanned text, signatures, stamps and line art, a plain threshold with Dithering set to None gives the cleanest result. For photos, a plain threshold loses the shading, and that is where dithering comes in.

Dithering spreads black dots so that, from a normal distance, the eye sees gray: dense dots look dark, sparse dots look light. It is how newspapers, thermal receipt printers, screen printing and laser engravers show photos when they can only make a mark or no mark. You find it under Dithering when the style is Black & white.

A grayscale image for laser engraving needs a little preparation, because most lasers either fire or do not fire at each dot: dark areas get burned and light areas stay. The Laser engraving preset sets everything up in one tap: Black & white, Jarvis dithering, threshold 128, contrast +20 and a size in mm at 318 DPI.

The key setting is resolution. Your laser software has a line interval, or a lines per inch (LPI) value: how many lines it engraves per inch. Many diode lasers work well at about 254 to 318 LPI, which is a line spacing of 0.1 to 0.08 mm, and CO2 lasers are often run somewhere between 250 and 500, depending on the material. Open More options, tick Set the size in mm, enter the width you want to engrave and pick the matching DPI: 254, 318, 400 and 508 are in the list next to 150, 300 and 600. Then one pixel is one dot, and the laser software does not have to resize or re-dither the picture.

Engraving tends to darken mid-tones, so a picture that looks slightly too bright on screen often engraves best; check the preview and raise Brightness or Gamma a little if needed. Light woods take dithering well. On slate, black anodised aluminium and painted surfaces the engraved mark is lighter than the material, so tick Invert (negative) to get a positive result. Always test a small piece on scrap first, because every machine and surface behaves differently.

When you use a dithered file from here, set your laser software to pass the picture through without dithering it again, so the dots are not processed twice. If you prefer your software to do the dithering itself, save a plain Grayscale file at the right size instead.

A grayscale image for CNC relief carving, a height map or a 3D printed relief works differently: the gray value becomes a height. In most relief software white is high and black is low, with gray in between. A depth map therefore wants smooth gradients, not dots, which is why the CNC / 3D relief preset uses Natural grayscale with no dithering.

Smoothing (CNC relief) in More options adds a blur of 0 to 20 px. Photos are full of tiny noise and sharp edges, which turn into spiky, rough toolpaths. A blur of 2 to 5 px gives smooth surfaces; more gives a soft, rounded relief. The preview applies the same smoothing to its smaller copy, so what you see matches the full-size file.

If your software reads the map the other way round, with black as high, tick Invert (negative). Programs differ here, so check what yours expects and carve a quick test. Save as PNG: it keeps every gray level exactly and is the safest file type for a depth map.

Making a black and white image online free here costs nothing and adds no watermark. The result is made at the full pixel size of your original; the preview, which is scaled down to fit your screen, is only for looking.

Black and white results are saved as PNG with Automatic file type. PNG is lossless, so every dot stays sharp, while JPG would smear the hard edges into gray blocks and often make the file larger, not smaller. For a page that has to go out as a document, Image to PDF puts the pictures on pages, and Compress Image makes gray photos lighter if a site has an upload limit.

The saved files contain the picture only: camera details, dates and location from the original are not copied in. If you want to clean an original photo as well, Remove Metadata does that.

The Adjust card works in every style, so this black and white image converter can rescue a dull or dark photo before the gray step. All changes appear live in the preview.

Brightness, from -100 to 100, makes the whole picture lighter or darker. Contrast, from -100 to 100, pushes light tones lighter and dark tones darker; positive values give punch, negative values a soft, faded look. Gamma, from 0.30 to 3.00, changes the mid-tones while leaving pure black and pure white alone: above 1 opens up shadows and brightens faces, below 1 deepens mid-tones and adds mood.

Invert (negative) swaps dark and light. Use it to turn a scanned film negative into a positive, to make white-on-black art, or to flip a depth map or an engraving for materials that mark light. In Black & white mode, Brightness and Contrast also shift which pixels fall on each side of the threshold, so they are a quick way to fine-tune a scan.

Preparing a black and white image for printing starts with the size. Open More options, tick Set the size in mm, type the width and pick a resolution from 150 to 600 DPI; the height follows the shape of the picture. At 300 DPI, a width of 100 mm becomes 1181 pixels, and at 600 DPI it becomes 2362. The DPI value is also written into PNG and JPG files, so print programs show the right physical size.

300 DPI is the usual value for photos and documents. For crisp line art and text, 600 DPI keeps edges very sharp. Gray prints the same on any printer and saves colour ink, and pure black and white with a dithering pattern is what thermal label printers and many stencil makers need.

Printers add their own screening to gray tones, so a dark photo can print heavier than it looks on screen. Raise Gamma a little, to around 1.2, if your prints come out too dark. If you only need to change the DPI of a file without converting it, Change DPI does that, and Resize Image sets an exact pixel size.

A black and white photo with color pop keeps one colour, such as a red coat, a yellow taxi or a bunch of flowers, and turns everything else gray. Choose the Colour pop style or preset, then click the picture on the colour you want to keep; the preview updates at once. The Colour kept slider sets the same thing by hue, from 0 to 359 degrees.

Range sets how wide the kept colour band is, from ±5° to ±90°. A narrow range keeps only one exact shade; a wider one includes its neighbours, for example orange next to red. Soft edges blends the border between colour and gray so the change does not look like a hard cut-out. Pale and grayish areas always turn gray, because only clearly coloured pixels are kept.

The gray part uses the gray method and Adjust sliders you set, so you can darken the background with contrast and let the colour stand out even more. It works best when the colour you keep appears only in the subject. Skin tones are close to orange and red, so a red pop may keep faces too; narrow the range if that happens, or cut the subject out first with Remove Background.

Automatic is the default. Black & white results are always PNG, so the dots stay sharp. Otherwise a PNG, GIF or BMP picture is saved as PNG, a WebP as WebP, and JPG and HEIC photos as JPG, which is small and accepted everywhere.

Choose PNG to keep every gray level exactly, for depth maps, scans and graphics. Choose JPG for the widest support; it is saved at high quality. Choose WebP for websites, where it gives small files. PNG and WebP also keep transparent areas of the original, which JPG cannot store.

On iPhone and iPad, open this page in Safari or another browser, tap Select pictures and pick from Photos or Files; HEIC photos work directly. Saved files go to Downloads in the Files app, and Save Image or Share moves them into Photos.

On Android, pick from the gallery or file manager, and results land in the Downloads folder. On Windows and Mac, any current browser works: drag pictures from a folder, or copy one and paste it with Ctrl+V. The ZIP opens with the built-in tools of both systems.

Your pictures are read, converted and saved by your browser, and nothing is sent to our server: no file, no preview, no copy. That makes it safe for family photos, ID documents and work files. Only the page itself loads from our site, and your last settings are kept in your browser's own storage, which you can clear at any time.

Each picture is opened by the browser, turned the right way up and drawn onto a canvas at full size, or at the size you set in mm. Every pixel is turned into a gray value with the method you chose and adjusted for brightness, contrast and gamma. Depending on the style it then stays gray, is compared with the threshold and dithered, or is mixed with its original colour for colour pop. The canvas is saved as PNG, JPG or WebP, with the DPI added when you set a size.

Converted pictures often go on to other jobs. Crop Image trims a photo to the part you want to engrave or print, and Upscale Image enlarges a small picture before printing. For cutting lines rather than engraving, PNG to SVG turns a black and white logo into a vector file, and Add Border frames a finished gray photo.