Is there a halftone generator that runs locally in the browser without uploading my photo?

Yes, several. MakeHalftone says there is no upload endpoint at all and that it works offline once loaded. HalftoneDots, Jukebox Print's Bitmap Maker, InstantGradient (WebGL shader), Halftone Maker, Vector Witch, siutil, Grayscale Image and Yan's Halftone Generator all state that processing happens in your browser and the image is never uploaded. To verify any of them, open DevTools, watch the Network tab while you process a photo, or load the page, go offline, and see if it still works.

What is the best free halftone generator for a gig poster?

For a single-colour screen-print or photocopy poster, MakeHalftone gives you free vector SVG and 300 DPI PNG with dot, line, ring or diamond screens. For a dirtier xerox look, run the photo through Jukebox Print's Bitmap Maker (threshold, Atkinson or halftone dots) and export SVG or PDF. For a two-colour risograph-style poster, Yan's Risograph Effect separates the photo into four inks with offset screens and misregistration, but it exports a PNG up to 1400px, so it suits web flyers and small prints rather than large posters.

Which free halftone tools export SVG vector files?

MakeHalftone, Jukebox Print's Bitmap Maker (also PDF), HalftoneDots and Vector Witch export SVG for free. Vector Witch needs a free account. Halftone Maker exports SVG only on its paid Pro plan, listed at $8 a month or $48 a year when we checked. MagicPattern, InstantGradient, siutil, Grayscale Image and Yan export raster images only.

Can I make a CMYK halftone online for free?

MagicPattern's CMYK Halftone Generator is the most flexible free option: separate cyan, magenta, yellow and black dot screens, each at an angle you set, exported as PNG. MakeHalftone has a CMY colour simulation, which it describes as an artistic effect rather than print separations. Yan's Risograph Effect separates the image into CMYK plates at fixed angles of roughly +15.5, -15.5, 0 and 44.7 degrees, with deliberate misregistration. None of these replace a prepress separation from your print shop.

Why does my halftone look muddy when I resize it?

A halftone is a pattern, so scaling it changes the dot frequency. Shrinking a raster halftone merges the dots, and enlarging it blurs their edges. Export at the final print size (MakeHalftone shows print width at 300 DPI), or export SVG so the dots stay sharp at any size. Also make a proof print: paper, ink spread and screen mesh all change how dots read.

Free Online Halftone Generators Compared: Which Keep Your Photo on Your Device?

Editorial disclosure: Yan's Halftone Generator and Risograph Effect are made by the team behind this site. Every other tool was checked against its own public pages in October 2026. "Not stated" means the site does not say. It does not mean the answer is no.

The two questions this guide answers

"I'm designing a gig poster and want a gritty halftone or photocopy look for the band photo. What should I use if I'm not a Photoshop person?"
"I want to add a halftone to a personal photo, but I don't want to upload it to some random server. Is there a tool that runs locally in the browser?"

The good news for both: in 2026, most of the halftone generators people recommend run in the browser, are free, and need no account. The differences are in the details that matter for print: dot shapes, CMYK, vector export, size limits, and whether the site actually tells you where your photo goes.

Comparison table

Tool	Free?	Sign-up	Local processing (stated)	Dot shapes	CMYK	Vector / SVG	Max export
MakeHalftone	Yes	No	Yes, "no upload endpoint at all"	Dot, line, ring, diamond	CMY simulation (artistic)	Yes, free	Web PNG or 300 DPI print PNG
MagicPattern (Halftone + CMYK Halftone)	Yes	No	Not stated	Dot pattern options (not listed)	Yes, separate tool, per-channel angles	No (PNG)	"High-resolution", not stated
Jukebox Print Bitmap Maker	Yes	No	Yes	Dots, lines, diamonds, stars, hearts + 14 dither/halftone styles	No	Yes, free (+ PDF)	PNG up to 8x
Halftone Maker	Free tier + Pro ($8/mo)	No	Yes, "not uploaded"	Dot, line and ring grids + stippling	Not stated	Pro only	Free: 1x PNG; Pro: hi-res PNG
InstantGradient	Yes (Pro pass optional)	No	Yes, WebGL shader	Dot, line, square; square or hex grid	No (original colours or single ink)	No	Free 1080p; Pro 4K / native up to 4096px
HalftoneDots	Yes	No	Yes	Circle, square, diamond	No	Yes, free	PNG 960 / 1600 / 2400px long edge
Vector Witch	Yes	Free account required	Yes	Dot, square, line	No	Yes (+ PNG, JPG, BMP)	Not stated (25MB input)
Yan Halftone Generator / Risograph	Yes	No	Yes, Canvas 2D	Dotcross (circle to cross), stipple, crossmarks	Risograph: 4 plates, fixed angles	No	PNG, 1400px long edge

1. MakeHalftone

Best for: a free, print-minded halftone with vector output and a clear privacy promise.

MakeHalftone is built for screen printing, DTF transfers and posters. You choose dot, line, ring or diamond screens and rotate them anywhere from 0 to 180 degrees. Sliders cover spacing, dot size, threshold and contrast, and there are presets: Newsprint, Bold ink and Fine detail.

Export: PNG at web resolution or 300 DPI print resolution, or a true vector SVG, with an optional transparent background. No watermark, no account, no subscription.
Colour: a CMY colour simulation, which the site says is "an artistic colour effect, not print separations."
Privacy: "Processing happens in your browser with the Canvas API. There is no upload endpoint at all." It also says the tool works offline once loaded.
Batch processing and true CMYK separations are listed as "coming later."

Gig-poster verdict: the best starting point. Use the Bold ink preset, push contrast, and export SVG for the print shop.

2. MagicPattern Halftone and CMYK Halftone

Best for: full-colour, offset-print-style CMYK dots with real control over each channel.

MagicPattern has two separate tools. The Halftone Generator is single-ink on a paper colour. You control dot size, sharpness, screen angle and dot pattern, with presets for newsprint, comic, sepia, pop art and risograph. The CMYK Halftone splits the image into cyan, magenta, yellow and black screens, each at its own angle. It also has dot scale, sharpness, a paper-white toggle, and multiply or subtractive blending.

Free, no signup, commercial use allowed. Export: PNG.
Privacy: not stated. The pages say the tool is "free to use in your browser" and that "images you upload remain yours." Neither says whether processing stays on your device.

Gig-poster verdict: pick this when the poster is full colour and you want visible CMYK rosettes.

3. Jukebox Print Bitmap Maker

Best for: the photocopied, 1-bit, zine-and-xerox side of "gritty."

The Bitmap Maker from print company Jukebox is really a dither tool with a halftone mode. It offers 14 styles: eight error-diffusion algorithms (Floyd-Steinberg, Atkinson, Jarvis, Stucki, Burkes, three Sierra variants), three ordered Bayer matrices, a halftone dot screen, hard threshold and noise. It can also rebuild the photo from stars, hearts, diamonds, dots or engraved lines.

Export: PNG up to 8x resolution, SVG (every pixel becomes a vector shape) or PDF. All free, no watermark, no signup, no limit on how many.
Privacy: "Everything runs in your browser, so your image never leaves your device."
Ink and paper colour presets include riso red, Game Boy green and fluorescent orange.

Gig-poster verdict: for a flyer that looks like it went through a cheap photocopier, use hard threshold or Atkinson here before you reach for dots.

4. Halftone Maker

Best for: stippling (dotwork) and line halftones, if you are willing to pay for vectors.

Halftone Maker does dot, line and ring grid halftones plus stippling, with a real-time preview. "No account needed, and your images are not uploaded."

Free plan: all halftone controls, commercial use, unlimited 1x PNG export, offline launch.
Pro plan (listed at $8/month or $48/year when we checked): SVG vector output, high-resolution PNG and batch processing.

Gig-poster verdict: good for an engraved or dotwork look. Note that the SVG headline feature is paid.

5. InstantGradient Halftone Generator

Best for: quick colour halftones with a hex grid for the comic Ben-Day look.

InstantGradient is a mesh-gradient app with a halftone mode. It renders dot, line or square marks on a square or hexagonal grid, with size, angle, radius, softness and contrast controls. It can keep the photo's own colours or render it as single-ink duotone.

Privacy: "Your image is read in your browser and processed there by a WebGL shader. It is never uploaded."
Free, no sign-up, no watermark. Free exports go up to 1080p; a paid Pro pass unlocks 4K and native size up to 4096px.

Gig-poster verdict: fine for social graphics. The 1080p free cap is too small for a printed A2 poster.

6. HalftoneDots

Best for: a no-fuss dot pattern with SVG and a transparent background.

HalftoneDots has circle, square or diamond dots with size, spacing, angle and contrast controls, a dot colour, and a white, transparent or custom background.

Export: PNG at 960, 1600 or 2400px on the long edge, or SVG with editable dot paths.
Inputs: JPG, PNG, WebP up to 10MB or 40 megapixels.
Privacy: "Processing stays in your browser; the editor does not send or store the image." No account.

7. Vector Witch Halftone Generator

Best for: laser engraving and cutting files.

Vector Witch turns photos into dot, square or line halftones meant for laser engraving ("black means engrave"), with an invert toggle for dark materials.

Export: vector SVG, plus PNG, JPG and BMP. Inputs up to 25MB.
Privacy: "The entire conversion runs in your browser — your images never leave your device."
Catch: it is free and uses no credits, but you need a free Vector Witch account to use it.

8. Yan Halftone Generator and Risograph Effect

Best for: private, watermark-free print textures with screen logic built in, at web and small-print sizes.

Yan's Halftone Generator is built around Dotcross. It draws a circle whose radius tracks tone, then switches to a cross once darkness passes about 31%, which holds shadow detail. A Bayer matrix nudges the readings so the marks do not lock into a moire grid. The same page offers Stipple (variable-radius dots), Crossmarks and Risograph.

The Risograph Effect is the colour case. It converts the photo to CMYK coverage and screens each plate at its own angle: roughly +15.5, -15.5, 0 and 44.7 degrees. Each plate is offset a little, like paper drift between passes, and the inks multiply onto a warm off-white paper with grain.

Free, no account, no watermark. Part of the 28-filter Texture Studio.
Local: rendered in your browser with Canvas 2D; the image is never uploaded. The site keeps anonymous page and feature analytics, never the image.

Where it is weaker, honestly:

PNG only, up to 1400px on the long edge (smaller images keep their size). Too small for a large printed poster.
No SVG or vector output.
No ink or paper colour pickers and no screen-angle control. You get three sliders: detail (screen coarseness), intensity and contrast. The risograph angles are fixed.

Also checked

siutil Halftone: round or square dots, spacing, angle, ink and paper colour. PNG at the original pixel size. "Processed in your browser · never uploaded."
Grayscale Image Halftone: dots, lines, diamonds or squares, PNG output, no signup. Processing is client-side. The site notes it is "a visual simulation, not a full CMYK prepress separation."
Vayce: a halftone effect with dot and background colour and an optional coloured-dots mode. A separate Photocopy Scan Lines effect controls toner crush, scan lines, vertical streaks and paper noise, which suits the xerox look. The site says "No uploads · No accounts."

Privacy: which ones keep your photo on your device?

This is the question to settle before you drop in a personal photo.

Say the image stays in the browser: MakeHalftone (and says it has no upload endpoint), Jukebox Print Bitmap Maker, Halftone Maker, InstantGradient, HalftoneDots, Vector Witch, siutil, Grayscale Image, Vayce and Yan.

Does not say: MagicPattern. That is not proof it uploads anything, only that the page makes no promise.

What "local" does and does not mean:

Local tools read the file with the browser's File API and process pixels in a Canvas or WebGL context. The image never needs to leave your device.
The page itself is still a website. Most of them, including Yan, load analytics about the visit, like page views or which filter you chose. That is not the same as your image, but it is not zero data either.
An account requirement (Vector Witch) ties your use to an identity, even if the image stays local.

How to check for yourself in 30 seconds:

Open the tool, then open DevTools and switch to the Network tab.
Drop in a test image and apply the effect.
Look for any request whose size matches your file. A local tool shows none.
Or load the page, switch off Wi-Fi, and process an image. If it works offline, the processing is local.

Which one should you pick?

Gig poster, one ink, going to a screen printer: MakeHalftone, exported as SVG.
Gig poster, full colour, visible CMYK dots: MagicPattern CMYK Halftone.
Gig poster that should look photocopied: Jukebox Bitmap Maker (threshold or Atkinson), then add dots if you want. Or Yan's Dither Converter for a 1-bit pass.
Riso-style two- or four-colour flyer for Instagram or a small print: Yan's Risograph Effect.
Laser engraving: Vector Witch.
Private photo, no account, no upload: any tool on the "say the image stays in the browser" list above, checked with the Network-tab test.

For the theory behind the dots and the riso process, read The Risograph Effect Guide and The 1-Bit Dither Guide.