Shortcuts
Drag the round handle (or anywhere on the stage) to move the seam. Every action here also has a button — these keys are optional shortcuts.
← / → nudge the seam
Space play / pause synced video
L / T / R pick Left / Tie / Right in Cull mode
1–6 switch compare mode
Scroll pan · Pinch / Ctrl+Scroll zoom · + / − / 0 zoom in/out/fit · double-click stage to reset
Privacy
Everything runs locally, in this browser tab. Your images and video are never uploaded — there is no server, no account, and no analytics anywhere in this app. Items sent in from Rendre arrive as a direct browser-to-browser message, not through a server either. Closing this tab clears everything; nothing is saved unless you explicitly download it.
Credits & license
Video export uses
mp4-muxer (Vanilagy, MIT License). Cull & rank and Tinct's blind test share the Glicko rating system (Mark Glickman, 1995). Built as a companion to
Rendre, Phil Renato's research renderer.
Non-commercial research software — everything you make with it is yours (see
LICENSE,
DISCLAIMER &
NOTICES alongside the app). Juxt™ and RendreJuxt™ are marks of Phil Renato — ideas and source may travel; the names may not.
Full LICENSE / DISCLAIMER / NOTICES text — embedded here so it travels with this one file, even if renato.design ever disappears
LICENSE.txt
JUXT — LICENSE
===========================================================
Copyright (c) 2026 Phil Renato. All rights reserved.
NON-COMMERCIAL RESEARCH SOFTWARE. Juxt is published as a
research artifact — a comparison and curation tool built
alongside Rendre — not as a commercial product. It is made
available for use, study, and teaching at renato.design free
of charge, without accounts, telemetry, or payment of any
kind.
WHAT YOU MAY DO
- Use Juxt in the browser for any purpose, including in your
own commercial design work: the comparisons, rankings, and
exports YOU make with it are YOURS, entirely.
- Study it. The source is one readable HTML file by design.
WHAT THIS LICENSE DOES NOT GRANT
- Redistribution, rehosting, mirroring, or resale of the
application, in whole or in part, outside renato.design.
- Use of the Juxt name to imply endorsement.
THIRD-PARTY COMPONENTS
- See NOTICES.txt for the full third-party license texts
(mp4-muxer MIT, IBM Plex Mono + Syne OFL) and the Glicko-1
rating citation used by Cull & Rank and Tinct's blind test.
LINEAGE. Juxt was built alongside Rendre (Phil Renato's
research renderer) — its video-export pipeline and dependency-
free ZIP writer/reader are ports of code first written for
Rendre — but Juxt is its own standalone tool, not a fork, and
takes anything you drop into it, from anywhere.
NO WARRANTY — see DISCLAIMER.md. Provided AS IS; no fitness
for any purpose is promised.
DISCLAIMER.md
JUXT — DISCLAIMER
===========================================================
Juxt is NON-COMMERCIAL RESEARCH SOFTWARE — a research
artifact published for study and teaching, not a commercial
product. It is provided AS IS, without warranty of any kind,
express or implied. Use it at your own risk.
WHAT JUXT IS. An A/B and multi-way comparison tool for images
and video that runs entirely in your browser: wipe, blend,
checkerboard, and diff-heatmap modes; a pairwise Cull & Rank
mode; a Tinct color-palette generator and blind preference
test. No account, no upload, no cloud — nothing you drop in
ever leaves your machine. Offline-capable once installed.
RANKINGS ARE A CONVERGENCE TOOL, NOT A VERDICT. Cull & Rank
and Tinct's blind test use the Glicko-1 rating system to
converge a big batch to a ranked order in relatively few
comparisons. That's a statistical aid to a real decision you
still make by looking — not an objective judgment of quality,
and not a substitute for your own eye.
TINCT'S COLOR MATH IS REAL, ITS OUTPUT IS EXPLORATORY.
Palettes are computed in real OKLCH color space and rendered
into honest contexts, but they are a generative starting
point — not color-managed proofs. Final print or production
color decisions need a managed pipeline.
EXPORT / IMPORT. Sweep-to-video export is a genuine
QuickTime-compatible MP4 (WebCodecs, with a WebM fallback on
browsers that lack it); ZIP export bundles whatever's loaded.
The .juxt project file is Juxt's own format — it opens
reliably in Juxt itself, at any later date, but isn't a
general-purpose archive format for other tools.
BROWSER REQUIREMENTS. Juxt needs no special GPU — any current
Chrome, Safari, or Edge is enough. Very old browsers lacking
WebCodecs fall back to a WebM export instead of MP4.
NOTICES.txt
JUXT — THIRD-PARTY NOTICES + ASSET PROVENANCE
===========================================================
Juxt is NON-COMMERCIAL RESEARCH SOFTWARE published as a
research artifact by Phil Renato (see LICENSE.txt + DISCLAIMER.md).
This file lists what it uses and where the bundled assets came from.
RUNTIME LIBRARIES (vendored in this download)
-----------------------------------------------------------
IBM Plex Mono — SIL Open Font License 1.1, © IBM.
Bundled as static woff2 files (400/500/600 weights) in vendor/font/
so the app stays fully offline-installable with no runtime fetch.
Syne — SIL Open Font License 1.1, © the Syne Project Authors.
Bold weight only, used for the RendreJuxt-branded wordmark (only
rendered when Juxt is launched with ?from=rendre — the default
Juxt wordmark stays IBM Plex Mono). Vendored locally the same way
as IBM Plex Mono above (vendor/font/syne-700.woff2).
mp4-muxer — MIT License
Copyright (c) 2022 Vanilagy
https://github.com/Vanilagy/mp4-muxer
Permission is hereby granted, free of charge, to any person
obtaining a copy of this software and associated documentation
files (the "Software"), to deal in the Software without
restriction, including without limitation the rights to use,
copy, modify, merge, publish, distribute, sublicense, and/or
sell copies of the Software, and to permit persons to whom the
Software is furnished to do so, subject to the following
conditions:
The above copyright notice and this permission notice shall be
included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
OTHER DEALINGS IN THE SOFTWARE.
CODE PROVENANCE (methods reused from Rendre, Phil's own prior app)
-----------------------------------------------------------
Juxt's video-export pipeline (WebCodecs VideoEncoder → mp4-muxer,
with a WebM/MediaRecorder fallback for browsers without WebCodecs)
and its dependency-free ZIP writer are ports of code first written
for Rendre (rendre-web, Phil Renato + Claude). No third-party
licensed code beyond mp4-muxer itself is involved.
The Glicko-1 rating system used by Juxt's cull/ranking mode is a
published algorithm (Mark Glickman, "The Glicko system," Boston
University, 1995) — the JavaScript implementation here was written
for Juxt from the public formulas, not copied from any Glicko
reference implementation.
PROVENANCE NOTE: Juxt's first working deploy (v00000-001) was
committed to the shared philrenato-web repo's history under a commit
labeled for an unrelated app ("glisten v214") — a one-time git mixup
during a shared checkout, resolved operationally with no data lost.
Noted here for anyone archaeologizing the launch.
BUNDLED ASSETS
-----------------------------------------------------------
The default "Sample A / Sample B" comparison pair shown on first
launch is generated procedurally at runtime (a small canvas
gradient + shapes script) — no photographs or third-party images
are bundled with this app.
TRADEMARKS
-----------------------------------------------------------
Juxt™ and RendreJuxt™ (the name this app takes when launched from
Rendre) are marks of Phil Renato. Ideas and source may travel; the
names may not. All other trademarks are the property of their
respective owners. "Rendre" is Phil Renato's own prior research app,
referenced here only to credit code lineage.
CONTACT
-----------------------------------------------------------
Phil Renato · renato.design · philrenato@gmail.com