I built a Shopify CSV alt-text preview. Looking for feedback

Ask & Offer
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1

Hi, I’m Boon, the founder of AltCaption.

I built a browser-based preview tool for merchants cleaning up missing product image alt texts based on uploaded product CSV. It does not write to Shopify for you (no risk!). You still need to review each draft and Shopify’s import preview before importing the CSV.

I’m looking for feedback from merchants who have done this cleanup:

  • Is a three-row preview enough to judge if this is good?
  • What would stop you from trying this with a backup export?

The AltCaption Shopify CSV preview is available without an account.

I built AltCaption. The preview is free. AltCaption also has a $19/month Pro plan after a 3-day card trial; the paid plan is for bulk processing and is not required to use this preview.

The AltCaption Shopify CSV preview is available without an account.

2

AltCaption’s 3-line preview is a smart way to judge the semantic quality of AI-generated alt text, but for multi-variant catalogs, “previewing quality” doesn’t guarantee “coverage survival on import.”

Two technical breakdown points that make generated alt text useless after bulk CSV import:

  1. Variant-Level ALT Coverage Gaps: In Shopify product CSVs, the ‘Image Alt Text’ column must be explicitly duplicated on every variant row. Previewing 3 sample lines looks clean, but if the CSV export leaves secondary size rows blank assuming inheritance, Shopify renders blank alt text metadata across sub-variant CDN assets.

  2. The WebP Ingestion Trap: If your catalog images reference raw supplier .webp URLs, Shopify’s background CSV worker quietly skips fetching the image binary. Your carefully previewed AltCaption text gets attached to an empty media container that never successfully rendered.

Pre-normalizing image formats (WebP to JPG) and ensuring 100% variant-row ALT coverage locally before import ensures your AltCaption text actually lands on live CDN assets. A local browser tool like EasyCatch transpiles supplier WebP to high-res JPG inside your browser sandbox and generates Matrixify-compliant ZIPs with pre-mapped variant ALT metadata in 1 click. 100% Local-First.