Theme Check

Shopify Theme Check

Find what’s broken in your Shopify theme

Upload your theme export and get a readable report of every problem we find — the file, the line, and what to change. No app, no store access, nothing to configure.

No Shopify login
No app to install
Your theme is deleted after the scan

How it works

From export to fix list in three steps

No account, no configuration. The whole thing takes about a minute, most of it waiting on Shopify's export email.

Export your theme
Download the theme as a .zip from your Shopify admin. Two clicks — the guide below shows exactly where they are.
Upload the archive
Drop the .zip in the box above. It is unpacked into a temporary folder, every Liquid file is scanned, then the copy is deleted.
Work through the report
Each finding names the file and the line. Filter by severity or by check, and start with the errors.

Step by step

How to download your theme file

Shopify keeps the export behind a menu and then emails it to you. Here is exactly where to click.

1
Open Online Store
The export lives on the same page as your themes.
1. In the admin sidebar, click Online Store under Sales channels.
2. Your themes are listed on that page — no submenu needed.
2
⋯ → Download theme file
This works on the live theme and on any draft.
1. Find the theme you want to check — the live one is tagged Active.
2. Click the ⋯ button next to Edit theme, bottom-right of the theme card.
3. Choose Download theme file.
3
Grab the .zip from your email
Shopify does not hand the file over directly.
1. Shopify emails a download link to your staff account address — usually within a minute.
2. Click theme export in that email to download the archive.
3. Drop it in the box at the top of this page, still zipped.

What we look at

Checks that run on every upload

Liquid, JSON and locale files are all scanned. Every finding lands in the report with its file, its line and the rule that raised it.

MatchingTranslationserror
A locale file is missing a translation the other locales define.
TranslationKeyExistserror
A translation key with no matching entry in the default locale.
MissingTemplateerror
A render or include pointing at a template that is not in the theme.
MissingAsseterror
An asset_url for a file the theme does not actually ship.
UnknownFiltererror
A filter Shopify does not provide — the output silently comes out empty.
LiquidHTMLSyntaxErrorerror
Markup the Liquid parser cannot read, such as an unclosed tag.

OrphanedSnippetwarning
A snippet no other file renders — dead weight you can delete.
UnusedAssignwarning
A variable that is assigned and then never read.
UndefinedObjectwarning
An object that does not exist in the rendering context it is used in.
VariableNamewarning
A variable name that breaks the theme's snake_case convention.
DeprecatedFilterwarning
A filter Shopify has replaced, img_url and friends.
DeprecatedTagwarning
A Liquid tag Shopify has replaced with a newer form.

ImgWidthAndHeighterror
An img tag with no width and height — the usual cause of layout shift.
ParserBlockingScripterror
A script that holds up first paint instead of using defer or async.
RemoteAssetwarning
An asset served off a third-party domain rather than Shopify's CDN.
DeprecateLazysizeswarning
The lazysizes library where native loading="lazy" now does the job.
DeprecateBgsizeswarning
The bgsizes library, superseded by native lazy loading.
HardcodedRouteswarning
A storefront path typed by hand instead of going through routes.

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FAQ

Before you upload

Do I need to install anything?

No. You upload a theme export and we do the rest — no app, no Shopify login, no access to your store.

What happens to the file I upload?

The archive is unpacked into a temporary folder, scanned, and deleted as soon as the scan finishes. What is kept is the report: the findings, plus the single line of code each one quotes.

How large can the upload be?

Up to 25MB, comfortably more than a real Shopify theme export. Anything bigger is rejected before it is read.

Can I share the report?

Yes — every report gets its own URL. It is unlisted rather than private, so anyone with the link can open it.

Is this the full Theme Check rule set?

Not yet. Today it runs the four checks listed above across every Liquid file in the theme. More rules are on the way.

Find what’s broken in your Shopify theme

Export your theme

Upload the archive

Work through the report

Open Online Store

⋯ → Download theme file

Grab the .zip from your email