Best Free Online Halftone Generators, Tested Against a Real Print Job

What's the best free online halftone generator?

Depends what you're doing next with the file. For a fast raster preview, ezgif's halftone filter gets you a result quickest. Want a real CMYK separation look? Magic Pattern's CMYK Halftone Generator is the closest simulation of the three. But if that file has to survive contact with an actual press or screen-print shop, Halftone Maker is the only one that exports true vector geometry instead of a fixed-resolution raster.

A halftone generator turns a continuous-tone image into a pattern of dots or lines whose size and spacing simulate shading — the technique behind newspaper photos and screen-printed art. We ran the same source photo through all three, then asked the question that actually matters once you're done playing with sliders: what would a print shop accept without you redoing the file in an editor first?

How do Magic Pattern, Halftone Maker, and ezgif actually compare?

Magic Pattern's CMYK Halftone Generator simulates offset separation directly. It gives you individual dot scale, angle, and sharpness controls per channel — cyan, magenta, yellow, black — plus a multiply-vs-subtractive blend toggle and a paper-white background option. There's no field labeled LPI; dot scale is the closest proxy, and export is PNG only. It's free, needs no signup, and the output is cleared for commercial use.

Halftone Maker treats the halftone as vector geometry from the start. Grid spacing stands in for LPI, screen angle is adjustable with 45° offered as the print default, and you can pick from a dozen dot and line shapes plus two-color, gradient-map, or source-color modes. The free tier caps canvas resolution; a paid plan removes that ceiling. Export includes true SVG with optional shape merging, alongside PNG at up to 6x scale.

ezgif's halftone tool is a filter bolted onto a general GIF and image editor, not a dedicated print tool. You get a handful of fixed patterns — newspaper dots, circular screens at set sizes, ordered dither — and a single threshold slider. No independent size, spacing, or angle control. It does handle animated GIFs frame by frame, though, which the other two don't touch at all.

kott's own halftone effect sits closer to Halftone Maker in intent: explicit LPI-equivalent spacing, named screen angles, export built for a 1-bit or limited-palette pipeline rather than a decorative filter. Where it's honestly behind the other three right now: no CMYK four-channel separation mode like Magic Pattern's, and no browser-native SVG export yet. Output goes through the same raster path as any other kott render.

Here's the honest verdict. Need a real four-channel separation preview? Use Magic Pattern. Does the file have to leave the browser as something a print shop can scale without re-rasterizing? Use Halftone Maker. Just want to see the effect on a GIF in ten seconds — ezgif wins on speed and nothing else here touches it. kott's version earns a look when halftone is one step in a longer dither or riso workflow you're already running in the app, not when a standalone CMYK separation is the whole job.

What does LPI mean, and why don't these tools show it?

Screen frequency, measured in lines per inch (LPI), is the spacing of the halftone grid itself. That's a different number from printer resolution, measured in dots per inch (DPI) — a single halftone dot at a given gray level is actually built from many printer dots, and confusing the two is the most common mistake in halftone prep. Adobe's own guidance puts the working ratio at 1.5 to 2 times: a 150 LPI screen wants roughly 225-300 PPI source art to hold detail.

None of the three tools put a number labeled "LPI" anywhere in their interface. What you actually get is a proxy — Magic Pattern's dot scale, Halftone Maker's grid spacing. Decide your target device first, before you touch either slider. Garment screen printing generally wants 45-65 LPI so the mesh count can physically hold the dots. Riso and photocopier-style output looks best around 65-85 LPI. Offset or magazine printing can run 133-300 LPI. Then treat the slider as a dial you're calibrating toward that number by test export, not a setting with one obvious correct value.

Why does screen angle matter for halftone printing?

Standard print angles exist for one reason: overlap two or more color screens at the wrong angles and the dots interfere, producing a visible pattern called moiré instead of merging into the small rosette shapes a trained eye reads as smooth tone. 45° is the industry default for single-color work. Four-color separations spread cyan, magenta, yellow, and black across a standard set of angles specifically to keep that rosette clean.

Of the three tools, Magic Pattern is the only one with real per-channel angle control — which makes sense, since it's also the only one simulating a full CMYK separation where angle conflicts actually cause moiré. Halftone Maker exposes a single screen angle, enough for one-color or spot-color work but no help staggering four channels against each other. ezgif skips angle control entirely. If moiré and screen angle are the actual subject rather than a side effect, kott's screen angles and moiré on a riso press piece covers the same physics at riso scale, where the tolerances run tighter than offset.

Why does a halftone print darker than it looks on screen?

Dot gain. Every halftone dot physically grows between the file you exported and the piece that comes off the press or the platen. Ink spreads under mechanical pressure, and porous stock or garment fibers absorb more ink at a dot's edge than at its center. Dot gain is worst in the 40-60% midtone range — which happens to be exactly where these browser previews look most convincing, because that's where dots have the most open perimeter left to expand before they start touching their neighbors. A representative figure: roughly 23% dot gain at the 40% tone on a 150 LPI screen printed on coated paper.

None of the tools here — including kott's own halftone effect, currently — build in dot-gain compensation. The fix has nothing to do with software: generate slightly lighter than what looks correct in the browser, and always print a small swatch before committing to a full run. The same principle shows up one step earlier in a riso workflow. kott's 1-bit riso file prep checklist walks through it for that specific process.

What if you're printing on garments instead of paper?

None of the three tools above handle two things that are non-negotiable for dark-fabric screen printing or DTF transfer: background knockout and a white underbase. Skip the underbase and light ink printed directly on a dark shirt just disappears into the fabric.

Brandum's halftone generator is built specifically for that workflow — background knockout, a white-underbase option, and a live preview across garment colors, according to its own product page. We weren't able to load the full tool interface to verify those controls directly, so treat this as a lead worth checking yourself rather than a tested recommendation. Confirm the dot-size, angle, and export controls actually exist before you build a production file around it.

Do you need a dedicated halftone tool at all?

Already have Photoshop open? Its native Color Halftone filter covers basic single- or four-channel dot separation without leaving the app — no browser upload, no export round-trip. It's less flexible than any of the three tools above on angle and shape control, but for a one-off job it's often faster. kott's Photoshop Color Halftone vs. a dedicated tool piece walks through exactly where the built-in filter is enough and where it starts to fall short.

Want to see how your own source photo holds up? Run it through kott's halftone effect, settings preloaded — the same test we ran to write this piece.

Frequently Asked Questions

What LPI should I use for a free online halftone generator?

There's no universal number — it depends on the output device, not the tool. Screen printing on garments typically runs 45-65 LPI so the mesh count can hold the dots. Riso and photocopier-style prints usually look best around 65-85 LPI. Offset or magazine work can run 133-300 LPI. None of the three general tools tested expose an LPI field directly, so treat their dot-scale or grid-spacing slider as a proxy: start coarse, print a small test swatch, and adjust from there instead of trusting the on-screen preview.

Can I get print-ready output from a free online halftone generator?

Partially. Halftone Maker's SVG export is genuinely print-ready as vector geometry, but you still have to set your own screen frequency and angle downstream. Magic Pattern and ezgif export PNG only, so you're locked into whatever pixel dimensions you generated at — size up before you generate, not after, since scaling a halftone raster after the fact reintroduces blur or aliasing on the dot edges.

Why does my halftone print darker than it looked on screen?

Dot gain. Every halftone dot physically grows a little between the file and the final printed or pressed piece — ink spreads under pressure, and porous stock or garment fibers soak up more ink at the dot edges. The distortion is worst in the 40-60% midtone range, where a 150 LPI screen on coated paper can gain roughly 23% dot area. None of the tools tested compensate for this, so plan on a slightly lighter setting than what looks correct in the browser.

What's the difference between a halftone generator and a dithering tool?

Halftone varies dot size or spacing at a fixed grid to simulate tone — the technique behind newspaper photos and screen-printed shirts. Dithering (Floyd-Steinberg, Atkinson, ordered/Bayer) varies pattern and density pixel by pixel with no fixed grid, built for indexed or 1-bit color reduction rather than press separations. They solve overlapping but different problems — if dithering is actually what you're after, see kott's Floyd-Steinberg vs. ordered dithering breakdown.

So which one should you actually use?

Ezgif for a fast effect on a photo or GIF, nothing more. Magic Pattern when the job is a real CMYK separation look. Halftone Maker when the file has to leave the browser as something a print shop can scale without you re-rasterizing it. A garment-specific tool like Brandum's — verified yourself first — when the job is dark fabric with a white underbase. None of these settings replace a test swatch: dot gain means the piece in your hand will always run a little darker than the piece on your screen. Print small before you print the full run.