RGB to CMYK Converter
Turn any photo into a true 4-channel CMYK TIFF for print: profile-aware ink limits, live soft-proof preview.
or browse filesdrop an image here or paste
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Turn any photo into a true 4-channel CMYK TIFF for print: profile-aware ink limits, live soft-proof preview.
or browse filesdrop an image here or paste
This converter produces a real print-ready file, not a look-alike: the download is a 4-channel CMYK TIFF whose pixels are actual Cyan, Magenta, Yellow and Black ink values, with an ICC profile embedded and the resolution tagged at 300 DPI. Photoshop, InDesign, Illustrator, Affinity and professional RIP software open it directly as a CMYK document. Load a JPG, PNG or WebP, pick the profile that matches your print job, and download - the whole conversion runs in your browser, so the image never leaves your device.
The preview is a split view with a draggable divider: your original RGB on the left, the printed result on the right, so the difference is impossible to miss. The proof side is a small press simulation - real process ink colors (which are impure: cyan swallows some green, magenta some blue), halftone coverage with dot gain, and the paper tint of the chosen stock. That is why vivid screen colors visibly dull the way they do in actual print: pure RGB red comes back as press red, electric blue lands near dark violet, and newsprint warms the whole image on its off-white paper. Switching profiles updates the proof live, so you can drag the divider and compare how the same photo survives each stock before committing.
Each profile drives the conversion differently, in two ways that matter on a real press. Black generation (GCR) decides how much of the gray component moves from expensive three-ink gray into the black channel - European coated profiles run heavier black, newsprint the heaviest. The total ink limit caps how much ink can land on one spot of paper: 300% for SWOP and ISO standards, 330% for GRACoL and FOGRA39 sheetfed work, 280% for uncoated stock, and 240% for newsprint, which would otherwise smear. This converter enforces the limit by scaling the colored inks while keeping black - shadow detail survives while the total stays printable.
Print shops often specify an exact .icc profile. Choose Custom, upload that .icc or .icm file, and its bytes are embedded verbatim in the TIFF - the file arrives at the shop tagged exactly as requested. Only CMYK output profiles are accepted; the tool checks the profile's signature before using it. The presets embed a complete ICC profile built from this page's own press model and named after the preset (for example "US Web Coated (SWOP) - imageonline.io press model"), so Photoshop, GIMP or a print shop's RIP shows the TIFF the way the preview showed it. It is not the official SWOP, GRACoL or FOGRA39 profile: the ink values come from a formula - black generation and an ink limit per paper - not from a conversion through those standards' measured tables. A custom .icc is embedded as the label the shop asked for, and the ink values are still made by the same formula. When a printer insists on a separation made with their exact profile, convert with it in Photoshop or InDesign. There is also a JPG proof download for quick sharing - it holds the soft-proofed preview, since JPG itself cannot carry 4-channel CMYK from a browser.
Screens make color with light (red, green, blue added together); presses make it with ink (cyan, magenta, yellow, black subtracted from white paper). An RGB file handed to a press pipeline gets converted somewhere along the way - by software you do not control, with settings you never saw, and sometimes with ugly surprises in exactly the saturated colors a brand cares about. Converting yourself shows you the color shift first, in the preview, so you can deal with it before the file leaves. For plain format conversion without the CMYK color work, the converter handles PNG, JPG, WebP, TIFF and more.
Load the image, choose the CMYK profile your print shop expects - SWOP for North American web offset, GRACoL for sheetfed, ISO Coated/FOGRA39 for Europe, or upload their exact .icc - and download the TIFF. The file contains genuine 4-channel CMYK pixel data, not an RGB image with a label.
Really CMYK: the TIFF stores four 8-bit ink channels per pixel (photometric Separated, InkSet CMYK), which is what design software checks for. Opening it in Photoshop shows a CMYK document with separate C, M, Y and K channels.
Ask your printer - it depends on press and paper. As defaults: US Web Coated (SWOP) for North American magazine-style work, GRACoL for high-quality US sheetfed, ISO Coated v2 / FOGRA39 for European coated paper, PSO Uncoated for uncoated stock, Newsprint for newspapers. If the shop sent you an .icc file, use Custom and embed exactly that.
Because that is what ink on paper does. Process inks are impure and cover a smaller color range than a glowing screen, so vivid reds, greens and blues cannot be reproduced at full screen intensity - and deep shadow colors additionally get trimmed by the paper's total ink limit. The preview simulates exactly that, with the divider letting you compare against the original; newsprint changes the most, coated sheetfed stock the least.
The maximum ink coverage a press allows on one spot, summed over all four channels - 300% is common for coated work, less for absorbent papers. Exceeding it causes drying problems and muddy shadows. This tool enforces the profile's limit during conversion, keeping black and trimming the colored inks.
Not completely, and no converter can: CMYK ink covers a smaller range of colors than a screen, so the brightest reds, greens and blues always dull a little in print. What you control is when you find out. The divider in the preview shows which colors shift before you download, so you can adjust the original, or pick the profile of the paper you actually print on, instead of finding out at the press. Keep the RGB original and convert a copy.
PNG cannot hold CMYK at all - the format only knows RGB and gray - so the print-ready CMYK version of a PNG is a TIFF, which is what this page writes. Load the PNG or JPG as it is. The JPG proof in the download menu is an ordinary RGB picture of the proof for sharing, not a CMYK JPG.
No. The conversion, the soft proof and the TIFF encoding all run in your browser on your device. Nothing is transmitted, and the tool works offline once the page is open.