See Exactly What Gets Blurred — SnapSlim Now Shows a Before/After Mosaic Preview

You turned on the mosaic toggle. The photo compressed. But now you’re staring at the thumbnail wondering: “Did it actually blur the right areas? Can I see what changed?”

Until today, you had to just trust the process and compare manually after downloading.

Not anymore.

SnapSlim just added a Before/After comparison preview directly inside the compression tool — a slider that lets you drag left and right to see exactly what the mosaic changed, before you save anything.

What’s New: The Mosaic Comparison Feature

When you compress an image with the Skin Mosaic toggle turned on, you’ll now notice:

1. A Pink Border Around Each Thumbnail

Every image that had the mosaic applied gets a distinctive pink border — so you can instantly tell at a glance which images were processed and which weren’t. No need to remember what you turned on.

2. A “Compare Preview” Button on Every Thumbnail

Below each mosaiced thumbnail, a 🔍 Compare Preview button appears. It’s always visible — no hovering, no hunting. One tap opens the comparison view.

3. An Interactive Before/After Slider

When you tap the button, a full comparison modal opens with three viewing modes:

The slider is the most useful: drag the divider toward the left to see more of the original, drag right to see the blur result — in real time, at full resolution.

Why This Matters

The Problem With “Blind” Mosaic

Face and skin detection isn’t magic. It works by analyzing color tones — which means:

• It does catch faces, arms, and exposed skin in typical photos
• It might miss people in low-light areas or with unusual skin tones
• It might partially blur areas you didn’t intend (like a wooden table with warm tones)

Without a preview, you’d have to download the file, open it, zoom in, realize something went wrong, go back, and try again.

With the comparison slider, you know immediately. If the mosaic missed an area, you see it in the preview. If it caught something you didn’t want blurred, you see that too.

Confident Sharing

The goal of the mosaic feature is to let you share photos responsibly — without accidentally exposing someone’s face online. But “responsible sharing” requires confidence that the tool actually worked.

The before/after slider gives you that confidence. You can verify the result before it ever leaves your browser.

How to Use It: Step by Step

Here’s the complete workflow from upload to verified download:

Step 1 — Upload your photo Open snapslim.site and drag your image onto the page (or click to select it).

Step 2 — Turn on Skin Mosaic Find the Skin Mosaic toggle in the options panel on the right. Switch it on. You’ll see a pink hint banner appear: “After compression, click any image to compare the original and mosaic result side by side.”

Step 3 — Let it compress Click Compress All. The tool will compress your photo and apply the mosaic in one step.

Step 4 — Click the thumbnail Once compression finishes, your thumbnail will have a pink border and a 🔍 Compare Preview button. Click anywhere on the thumbnail to open the comparison modal.

Step 5 — Drag the slider The slider starts at 50/50. Drag it left to see the original, right to see the blurred result. Use the Before and After tabs if you want a full, uninterrupted view of either version.

Step 6 — Download Happy with the result? Hit the Download button inside the preview modal — or close it and use the regular download button on the main screen. Either way works.

Real-World Scenarios Where This Helps

📸 Event Photos With Crowds

You photographed a street festival. There are dozens of people in the background. You apply the mosaic and want to verify that the main subjects (faces in the foreground) were properly handled, while the background crowd was also blurred.

→ Drag the slider and scan from left to right to visually confirm coverage.

🏫 School Event Photos

A parent group wants to share class trip photos — but every child’s face must be protected. Before sending the file to the group chat, the teacher wants to be 100% sure the mosaic worked.

→ Switch to “After” tab for a clean, full view of the processed image. If any child’s face is still visible, they’ll see it instantly.

🛒 Online Marketplace Listings

You’re selling a product. In one of the photos, a family member’s face is reflected in a glass surface. You’re not sure if the mosaic tool caught that reflection.

→ Zoom in on the “After” tab to check the specific area before downloading.

📱 Before Posting to Social Media

You want to post a cafe photo, but a stranger is clearly visible at the table next to you. You apply the mosaic, then use the slider to compare — seeing the original face vs. the blurred result side by side.

→ Peace of mind before you post. No second-guessing.

Privacy First — Even During Preview

One detail worth highlighting: the comparison preview is also 100% private.

The before image comes from your original file, stored in your browser’s memory. The after image is the mosaic result, also in your browser. Neither version is uploaded anywhere during the preview process.

The slider comparison, the modal, the download — everything happens on your device. SnapSlim never sees your photos.

This is especially important for sensitive content: medical images, ID documents with faces, confidential workplace photos. You can verify the mosaic result with complete confidence that the data isn’t going anywhere.

What the Mosaic Actually Detects

SnapSlim’s skin mosaic uses a color-range detection algorithm that works entirely in-browser using the HTML Canvas API. Here’s how to think about its coverage:

This is why the comparison preview is so valuable — it shows you exactly what was and wasn’t caught. If the detection missed something important, you can see that immediately and decide whether to adjust, skip the mosaic for that photo, or use manual cropping as a backup.

Combine the Mosaic With Other SnapSlim Features

The mosaic applies during compression, which means it stacks seamlessly with everything else:

• Resize to exact dimensions → Mosaic → Download
• Add a watermark → Mosaic → Download
• Convert to WebP → Mosaic → Download
• Remove EXIF/GPS data → Mosaic → Download

One upload. One compression step. Everything applied at once — with the new preview to verify before you commit to the download.

Try It Now

Open SnapSlim →

1. Drop in a photo with people in it
2. Turn on the Skin Mosaic toggle
3. Compress
4. Click the thumbnail with the pink border
5. Drag the slider

See exactly what changed — then share with confidence.

SnapSlim processes all images 100% in your browser. No account required. No server upload. No subscription. Free forever.