negs
New Negs now runs in your browser

NEGS ▸ BROWSER ▸ MAC ▸ WINDOWS ▸ LINUX

Your photos,
developed on film.

Negs runs your pictures through a physical simulation of film: the dyes, the print paper, the glow around highlights, the grain. Open a photo right here in your browser and watch it change.

Try it in your browser Download the app

Free · Nothing to install · Your photos stay on your device

Also a desktop app for Mac, Windows and Linux.

Based on spektrafilm by Andrea Volpato ▸
Negs running in a browser: a photo of Rome at dusk on Kodak Portra 400, with film, paper and camera controls beside it
  • PORTRA 800 ▸ 1
  • EKTAR 100 ▸ 2
  • EKTAR 100 ▸ 3
  • GOLD 200 ▸ 4
  • TRI-X 400 ▸ 5
  • GOLD 200 ▸ 6
  • GOLD 200 ▸ 7
  • EKTAR 100 ▸ 8

02 ▸ BEFORE / AFTER

Same photo. Now on film.

Surfers in the waves seen from above, developed in Negs on Kodak Portra 400 The same RAW file as macOS renders it by default RAW · Apple default Negs · Portra 400

Drag to compare. Surfers from above: the RAW as macOS shows it on the left, Negs with Kodak Portra 400 on the right.

  • PORTRA 400 ▸ 1
  • EKTAR 100 ▸ 2
  • PORTRA 800 ▸ 3

03 ▸ THE APP

A darkroom in a window.

In your browser, or as a native app on Mac, Windows and Linux. Pick a film, pick a paper, drag a slider, and watch the picture change as you move.

The Negs window: a photo of the Colosseum in a 35mm Kodak Ektar 100 frame, with film, camera and print controls on the right
  • Opens RAW files from most cameras, including 60 MP medium format, plus JPEG, TIFF and PNG
  • Crop, straighten, and add borders with each stock’s real edge print
  • Undo, keyboard shortcuts, pinch to zoom: it feels at home on Mac, Windows and Linux
  • Exports PNG, TIFF or JPEG at 8 or 16 bits and keeps your camera’s EXIF
  • Exports the current film and paper colours as a .cube LUT

04 ▸ THE FILM

Chemistry, not a filter.

Negs doesn’t guess what film looks like. It follows the light through the whole chain (film, enlarger, paper, scanner) using the published data for each stock.

01

Colour from the spectrum

Your photo is turned back into light, exposed onto the film’s three dye layers, printed onto paper and scanned. Colours shift the way they did on the real stock, because the same thing happens to them.

02

Halation

Bright lights bleed a warm red glow, the way light bounces back through real film. Street lamps, sun on chrome, candle flames.

03

Grain that lives in the image

Grain is simulated in each dye layer from how dense the film is at that spot. It sits inside the picture instead of being laid on top.

04

The developer’s bite

Development chemistry sharpens edges and deepens colour where tones meet, giving the crispness film has and digital lacks.

05

Paper matters

Choose the print paper too. The paper changes the look as much as the film does, just like in a real lab.

06

Print it, or scan it

Print the negative onto paper for the classic lab look, or skip the paper and scan the film directly.

05 ▸ BORDERS

Print it like a lab would.

Finish with a clean white border, a thin keyline, a black film edge, or the full 35mm frame, sprocket holes and all, printed with the stock’s own edge markings.

A bench on a terrace above a lake and mountains, with a white border
White border
Horse-drawn carriages in front of a palace, with a keyline border
Keyline
A bar at night with glowing shelves, with a black film border
Film edge
The Colosseum in a 35mm Kodak Gold 200 frame with sprocket holes and edge print
35mm frame

06 ▸ SPEED

Fast enough to play.

Drag a slider and the photo follows your hand: while you move, Negs develops only the pixels on your screen. Let go, and your GPU develops the whole photo at full resolution, grain and halation at their true size. That’s the frame you export, so Export is instant.

Drag

Live, at screen resolution

Every slider moves the picture as you drag, at the size your screen shows it.

Let go

The full photo, on the GPU

Under a second for 24 megapixels, about two seconds for 60.

Export

Instant

Export writes the frame you’re looking at. No waiting.

Full-resolution develop · 60 MP
  • Negs2.1 s
  • spektrafilm-rs4.1 s
  • Python spektrafilm108 s
Peak memory · 60 MP
  • Negs5.0 GB
  • spektrafilm-rs8.9 GB
  • Python spektrafilm27.8 GB

A Leica Q3 photo developed at full resolution on Kodak Gold 200 and Portra Endura, on a MacBook Pro with an M1 Pro and 32 GB. Times are the develop alone, without opening or saving the file; memory is the most each program used. Negs and spektrafilm-rs on the GPU; Python has no GPU path. At 24 MP: 0.9 s and 2.1 GB, against 1.3 s and 3.6 GB for spektrafilm-rs and 43 s and 13.7 GB for Python. All benchmarks, including the 64-bit Reference export and its Use less memory option.

07 ▸ STOCKS

Your film shelf.

Colour negative

  • Portra 160
  • Portra 400
  • Portra 800
  • Portra 800 +1
  • Portra 800 +2
  • Ektar 100
  • Gold 200
  • Ultramax 400
  • Fujicolor C200
  • Pro 400H
  • Superia X-TRA 400

Slide

  • Ektachrome 100
  • Kodachrome 64
  • Velvia 100
  • Provia 100F

Motion picture

  • Vision3 50D
  • Vision3 250D
  • Vision3 200T
  • Vision3 500T
  • Verita 200D

Black & white

  • Tri-X 400 Experimental
  • Double-X 5222 Experimental

Papers & print film

  • Portra Endura
  • Endura Premier
  • Supra Endura
  • Ultra Endura
  • Ektacolor Edge
  • Crystal Archive II
  • Ilford Multigrade RC
  • Vision 2383
  • Vision 2393

Kodak, Fujifilm and Ilford stock names are trademarks of their owners. Negs is not affiliated with them.

08 ▸ IN MOTION

Watch a roll develop.

09 ▸ WHY NOT A LUT

A LUT changes colours. Film changes light.

A LUT looks at each pixel on its own and swaps its colour. Real film doesn’t work like that: light spreads through the emulsion, highlights glow, grain follows exposure and neighbouring tones pull on each other. Negs simulates all of it, so the look holds up where LUTs fall apart: skin, neon, deep shadows, bright skies.

The photo developed in Negs on Kodak Ektar 100 The same photo with a Kodak Ektar 100 LUT Ektar 100 LUT Negs · Ektar 100

Drag to compare. Both on Kodak Ektar 100: a film LUT on the left, Negs on the right.

10 ▸ CREDITS

Built on open science.

The film model at the heart of Negs comes from two open-source projects. Negs builds fast apps on top of them: in the browser, and native on Mac, Windows and Linux.

ORIGINAL

spektrafilm

Andrea Volpato’s spectral simulation of film and print. The physics and the stock data come from here.

 RUST PORT

spektrafilm-rs

turbasvin’s Rust port of spektrafilm, the codebase Negs started from.

11 ▸ DOWNLOAD

Load a roll.

Download Negs View source on GitHub

Free · Mac, Windows and Linux

Negs for Mac

Download the .dmg

macOS 14 Sonoma or later · Apple silicon and Intel

  1. 01

    Drag to Applications

    Open the downloaded .dmg and drag Negs into the Applications folder.

  2. 02

    Open it once

    Double-click Negs. macOS says it can’t verify the app and won’t open it. Click Done (not Move to Trash).

  3. 03

    Allow it in Settings

    Go to System Settings → Privacy & Security, scroll down and click Open Anyway next to the message about Negs. Enter your password, then click Open.

Why the extra step? Negs isn’t notarized by Apple, which needs a paid developer account, so macOS asks you to allow it yourself the first time. Negs then updates itself: use Negs → Check for Updates….

Negs for Windows

Download the installer Portable .zip

Windows x64 · Experimental: the same film engine and GPU previews as the Mac app

  1. 01

    Run the installer

    It installs for your Windows account and adds Negs to Open with, without changing your default photo app.

  2. 02

    If SmartScreen warns you

    Click More info → Run anyway. Negs isn’t code-signed, which needs a paid certificate.

  3. 03

    Or skip the installer

    Extract the portable .zip and run Negs.exe. Keep the helper executables and the data folder beside it.

Windows doesn’t update itself yet: download the newer installer and run it over the old one.

Negs for Linux

Download Flatpak Download AppImage

x86_64 · Native GTK4 app · Vulkan driver for GPU acceleration, CPU fallback without one

  1. 01

    Flatpak

    For any distribution with Flatpak. Download the bundle above, then run this in your download folder:

    flatpak install --user negs-0.11.0-linux-x86_64.flatpak

    Flatpak fetches the GNOME runtime from Flathub if needed. Negs runs sandboxed and sees only the photos and folders you open. Use Open Folder… to see a whole folder in the film strip. To update, install the newer bundle the same way.

  2. 02

    AppImage

    A single file for Ubuntu 24.04 or newer, current Fedora, Arch and similar distributions. Download it above, then make it executable and run it from your download folder:

    chmod +x Negs-0.11.0-x86_64.AppImage ./Negs-0.11.0-x86_64.AppImage

    No installation needed. If your system has no FUSE, add --appimage-extract-and-run to the run command. To update, download the newer AppImage. Settings and presets stay in ~/.config/negs.

  3. 03

    Arch and Omarchy

    Or install the native package under ~/.local, no root needed. This command downloads the latest release and checks its SHA-256 checksum. Read the script first if you like: it’s short.

    curl -fsSL https://raw.githubusercontent.com/noahhaasis/negs/main/linux/get-negs.sh | sh

    Needs glibc 2.44, GTK 4.16+, libadwaita 1.6+, OpenBLAS and a Vulkan driver. On Omarchy these are normally present; elsewhere: sudo pacman -S --needed gtk4 libadwaita openblas vulkan-icd-loader. On distributions with older glibc, use Flatpak or AppImage instead.

    Run negs or find it in your launcher. To update, run the command again. To remove it: python3 ~/.local/share/negs/install.py --uninstall

Flatpak keeps settings and presets separately, in ~/.var/app/io.github.noahhaasis.negs. To move presets between Flatpak and the other versions, export them from one and import them in the other.

Questions

Is Negs free?

Yes. It’s free to download and open source under the GPL-3.0 (see the licence).

macOS or Windows warns me about Negs. Is it safe?

Both show that warning for apps that aren’t notarized (Apple) or code-signed (Windows), which needs a paid account or certificate. The source is on GitHub for anyone to check. Follow the Mac or Windows install steps: you only need to allow it once.

Which files can I open?

RAW files from most cameras, plus JPEG, TIFF and PNG. The Mac app uses Apple’s RAW support with a fallback decoder; the Windows and Linux apps use the rawler decoder.

Does it run on Intel Macs?

Yes, on Intel Macs that run macOS 14 or later. Negs is a universal app, so it runs natively on both Intel and Apple silicon. It is developed and tested mainly on Apple silicon, so if something looks wrong on an Intel Mac, please open an issue.

Is this a preset pack?

No. Presets and LUTs remap colours. Negs simulates the film, the paper and the light, which is why halation, grain and edge effects come out right.

Which systems does it run on?

Any recent browser, at getnegs.com/try: nothing to install, and your photos never leave your device. As a desktop app: macOS 14 or later (Apple silicon and Intel), Windows x64 with an installer or a portable build, and x86_64 Linux as a Flatpak, an AppImage or a native Arch/Omarchy package.