At a glance
Distribution of files in your BigCommerce file library by type (jpg, png, webp, gif, mp4, pdf, svg, etc). The headline insight: how much of your media is in modern formats (webp, avif, mp4) versus legacy formats (gif, bmp, uncompressed jpg). Modern format adoption is the single fastest Core Web Vitals win on a heavy-image catalogue.
Calculation
Calculated automatically from your BigCommerce data. See the At a glance summary above for what the metric tracks and the worked example below for a typical reading.Worked example
A US homewares brand on BigCommerce Plus with ~12,000 SKUs, snapshot at 12 Apr 26.
What’s interesting:
- Only 7.4% of files are webp, the modern format. JPG dominates at 67%. The single biggest CWV improvement available to this store is converting the jpg / png inventory to webp, the per-file weight drops 50-60% and LCP on mobile drops by ~400ms. That’s a top-3 ranking factor on Google for product searches.
- PNG is overrepresented at 19.6%. PNG is appropriate for transparent assets (logos, icons) but most merchants accidentally save photographs as PNG, which is 2-3x heavier than equivalent jpg or webp. Audit the PNG inventory: anything that’s a photograph should be webp; anything that’s a UI element should stay PNG (or move to SVG).
- GIF at 3.2% is concerning. GIF is 1995 technology; modern equivalents (animated webp, mp4 looping) are 3-10x smaller. 1,820 GIFs at 320 KB average = 580 MB of bandwidth that could be 60 MB. On heavy-image product pages this matters.
- 80 MP4s but no avif and no webm. Video is right-sized as MP4 here (small library), but the missing formats matter for Safari users (HEVC) and Android users (webm). Unless your theme provides format negotiation, you’re serving fallback formats unnecessarily.
- 17 GB total media library is healthy for a 12K-SKU store. That’s ~1.4 MB per SKU on average. A typical Shopify peer would be 2-3 GB smaller because Shopify’s CDN auto-optimises. The BC pattern of “merchant manages their own image weight” needs proactive maintenance.
- Run a bulk format conversion. BC’s API supports image upload but does not auto-convert; you need a tool. Apps like Image Optimiser by Sandhills Dev or Page Speed Optimiser can batch-convert.
- Identify the heaviest files first. A 4 MB hero image saved as PNG that should be 200 KB webp is worth 50 typical small files in CWV impact. Sort by size descending; convert top 100 first.
- Audit theme assets. Stencil themes ship with a default set of images; some legacy themes embed jpg / png assets that webp could replace.
- Convert GIFs to mp4 / webp. Animated webp has near-universal browser support now; mp4 with
loop autoplay mutedis the broadest fallback. - Set a webp-first rule going forward. Train the catalogue team to upload webp for new products; build it into the merchandising checklist.
Sibling cards merchants should reference together
Reconciling against the vendor’s own dashboard
Where to look in BigCommerce Control Panel: Storefront → File manager lists every file in the media library with type, size, and upload date. There is no native “by type” aggregation; you’d need to bulk-download the file list and group manually. For per-product image audit, Catalogue → Products → {product} → Images shows per-product image inventory. For storefront-side performance feedback, BC has no native CWV report; pair with PageSpeed Insights or Search Console for LCP / CLS / INP measurement. Why our number may legitimately differ from BC File Manager’s count:
Cross-connector reconciliation:
Same-metric documentation cross-reference:
shopify.file_types(planned)adobe_commerce.file_types(planned)
Known limitations / merchant FAQs
Should I convert all my JPGs to WebP at once? Bulk conversion is the right play, but stage it. Run a 100-product pilot first, measure LCP improvement on the affected pages, verify your theme renders webp correctly (some old themes hard-code jpg in template logic and break on format change). After a clean pilot, full-catalogue conversion typically takes 2-5 hours via API or via an image-optimiser app. My theme uses jpg by hard-coded references in the template, will conversion break it? Possibly. Older Stencil themes occasionally reference image filenames directly (<img src="banner.jpg">) instead of using BC’s image manager. Audit the theme files for hard-coded image references before doing a bulk filename change. The safest bulk-conversion approach is to keep the old filenames and serve format negotiation via a CDN (Imgix, Cloudflare Images), but BC stores typically don’t have a CDN of that sort layered on.
Why is webp adoption so low on most BC stores?
Three reasons: (1) BC’s native image upload doesn’t auto-convert; (2) BC’s CDN doesn’t transparently serve format alternatives based on browser support; (3) most merchants don’t proactively manage image format because the issue is invisible until a Search Console report flags slow URLs. The merchants who do manage actively are usually the ones with strong organic ranking.
Are SVG icons worth migrating to?
Yes for UI elements (logos, icons, decorative graphics). SVG scales infinitely, weighs 1-10 KB instead of 50-200 KB for equivalent PNG, and doesn’t need multiple resolution variants. Don’t use SVG for photography (it’s a vector format, photos won’t render meaningfully).
My catalogue has 50,000 product images, will the bulk conversion be expensive?
Cost varies by tool. Apps like Image Optimiser charge ~500-2,500 one-time. Free alternatives (running locally with cwebp + a script) are zero-cost but require dev time. Most stores recoup the conversion cost within 1-2 months via faster page loads improving conversion.
Does BigCommerce auto-convert images on upload?
No, BC stores whatever format you upload. Some BC themes use the <picture> tag with srcset to serve different sizes, but that’s a sizing optimisation, not format conversion.
Why does my GIF count keep climbing?
Usually a marketing-team behaviour: GIFs are easy to make in Canva or Photoshop and feel cheap to upload. Train the team to convert to looping mp4 or animated webp before upload; both are 5-10x smaller than equivalent GIFs at the same visible quality.
Do MP4 product videos help conversion?
Yes for higher-AOV products (above $50-100 typically). Product videos lift conversion 12-25% on furniture, fashion, beauty. They cost 1-5 MB per file though, so put them on a CDN or use lazy-load with a static image fallback.
My PDF count is 980, what are those?
Usually digital downloadables (assembly instructions, product datasheets, B2B catalogues). PDFs are heavy (1-5 MB typical) but only loaded on demand; they don’t affect storefront LCP. Audit them for outdated content but don’t worry about format conversion.
Should I delete unused / orphaned files?
Eventually, yes. Orphaned files don’t affect storefront performance directly but consume storage quota (BigCommerce charges per-GB above plan limits) and clutter the file manager. Run an annual cleanup of files not referenced by any product, page, or theme.