Do DualView and TwinLens both compare files locally in the browser?

Yes. Both tools run the comparison itself in your browser without uploading the files you are comparing. The key difference is sharing: as of June 2026, creating a TwinLens share link uploads your files to TwinLens servers (50MB cap, 14-day expiry, 5 links on the free tier), while DualView share links carry state and media URLs, or compressed content in the URL fragment, and never upload files.

Which tool has more analysis features?

DualView offers more analysis depth: SSIM, PSNR, MS-SSIM, and CIEDE2000 metrics, video scopes, blend and difference modes, plus PDF, CSV, JSON, text, audio, and 3D comparison. As of June 2026, TwinLens offers PSNR and SSIM for images and video but no scopes, and it focuses on images and video only. TwinLens is stronger on 4-up synced playback, folder review, and session recording.

Comparison Guide

DualView vs TwinLens

DualView and TwinLens are the two closest free, browser-based media comparison tools, and both run the comparison itself locally without uploading your files. They differ most in what happens when you share, how deep the analysis goes, and how many file types they cover. This page compares them honestly, as of June 2026.

Open DualView Verify privacy yourself

Quick Answer

If your intent is "compare images or videos with objective metrics, scopes, and many file types, and share without ever uploading," DualView is the more focused choice. If your intent is "review folders of images or videos 4-up with synced playback and record the session," TwinLens is strong there. Both are free and account-free for core comparison. The sharpest difference is sharing: TwinLens share links upload your files to their servers; DualView share links never upload anything.

Feature Comparison Table

Facts below are accurate to the best of our research as of June 2026. Products change; verify current TwinLens behavior and limits on twinlens.app before making decisions.

Question	DualView	TwinLens
Local comparison	Yes. Files are processed in the browser; nothing is uploaded.	Yes. Comparison runs in the browser without uploading files.
Sharing model	Share links carry comparison state and media URLs, or compressed content in the URL fragment. No file is ever uploaded; an offline HTML export is also available. See the URL schema docs.	Creating a share link uploads your files to TwinLens servers. As of June 2026: 50MB cap per share, links expire after 14 days, and the free tier includes 5 share links.
Objective metrics	SSIM, PSNR, MS-SSIM, and CIEDE2000, shown alongside the visual comparison.	PSNR and SSIM. No MS-SSIM or CIEDE2000 as of June 2026.
Scopes and analysis	Histogram, waveform, vectorscope, false color, focus peaking, zebra stripes, difference heatmap, blend modes, pixel inspector.	No scopes as of June 2026.
File types	Images, video, audio, PDF, CSV/Excel, JSON, text/prompts, and 3D models (GLB/GLTF).	Images and video, including AVIF, HEIC, and TIFF image formats. No audio, PDF, CSV, JSON, text, or 3D modes as of June 2026.
Playback	Synced playback with frame stepping, J/K/L shuttle, variable speed, loop regions, timeline, and markers.	Synced playback with automatic drift correction; playback speed caps at 2x as of June 2026.
Multi-view	Slider, side-by-side, blend, split (2x1, 1x2, 2x2), flicker, heatmap, and WebGL comparison shaders.	4-up synced playback for images or videos, with folder comparison review.
Recording and export	MP4, GIF, screenshots, animated sweeps, WebGL transition clips, and self-contained offline HTML export.	Records the live comparison session as WebM; snapshots to PNG.
Apps	Browser only.	Browser plus a desktop app.

When DualView Is The Better Fit

Metrics and scopes

DualView pairs the visual comparison with SSIM, PSNR, MS-SSIM, and CIEDE2000 plus video scopes, so you can quantify a difference instead of only eyeballing it.

Sharing confidential work

DualView share links never upload your files: they carry state and URLs, or compressed content in the URL fragment that browsers never send to a server. There is no size cap from an upload service, no link expiry, and no link quota.

Beyond images and video

Audio waveforms and spectrograms, PDF and document diff, CSV and Excel, JSON, AI prompt diff, and 3D model comparison all live in the same workspace.

When TwinLens May Be The Better Fit

TwinLens is a genuinely good tool, and the honest answer is that it wins some workflows as of June 2026: 4-up synchronized playback with automatic sync-drift correction, a polished folder-comparison experience, one-click recording of a live comparison session to WebM, AVIF/HEIC/TIFF image support, and a desktop app. If you mainly review folders of image or video variants 4-up and are comfortable with its hosted share model, TwinLens is a reasonable choice.

The Sharing Difference, Plainly

Both tools are private while you compare. The difference appears the moment you click share. TwinLens shares work by uploading your files to TwinLens infrastructure, which is why its free shares have a 50MB cap, a 14-day expiry, and a 5-link quota. DualView shares work by encoding the comparison into the link itself, either as parameters pointing at media you already host, or as compressed content in the URL fragment, so there is nothing to upload, expire, or cap. You can verify this yourself in the DevTools Network tab.

Sources Checked

This page reflects research as of June 2026. Verify current TwinLens features, share limits, and pricing on twinlens.app before relying on any claim here. If you spot something outdated, please tell us and we will correct it.