Theme ID Mismatch

Shopify CLI and Libraries
1

I have reproduced the issue on the latest CLI version.

Yes, I am on the latest version

I have searched existing posts and this report is not a duplicate.

Yes, this isn’t a duplicate

In which of these areas are you experiencing a problem?

Theme

Expected behavior

127.0.0.1:9292 shows the Development Theme.

Actual behavior

Get an error in the Terminal and the Session gets terminated

Reproduction steps

  1. Run shopify theme dev
  2. Open 127.0.0.1:9292 locally
  3. Get the error in the Terminal

Verbose output

│  Theme ID mismatch: expected 155700232341 but got 152271814805.                                                                                                                    │
│  Request ID: 4f3524c1-6cf5-4c85-9635-05f3e455a46d-1776515572                                                                                                                       │
│  URL:                                                                                                                                                                              │
│  This is likely related to an issue in upstream Shopify APIs.                                                                                                                      │
│  Please try again in a few minutes and report this issue:                                                                                                                          │
│  https://community.shopify.dev/c/shopify-cli-libraries/14

Operating system

macOS 15.7

CLI version

3.93.2

Shell

zsh

Nodejs version

v22.20.0

Related Github Issue

1 Like
2

Bug report: Theme ID mismatch — CLI crashes when storefront renderer ignores preview_theme_id on internal render request

Expected behavior

shopify theme dev should stay connected to the development theme and not crash.

Actual behavior

The CLI starts correctly and serves the development theme via ?preview_theme_id=DEV_THEME_ID, but then makes a second internal render request to /?_fd=0&pb=0 without the preview_theme_id parameter. The storefront responds with the live theme ID in the server-timing header, causing the CLI to detect a mismatch and crash — even though the original HEAD request with preview_theme_id returned the correct theme.

The CLI retries the session refresh 3 times before throwing the error, but the result is always the same.

Reproduction steps

  1. Have a store with a published (live) theme and a separate development theme
  2. Run shopify theme dev -e development with a shopify.theme.toml specifying the development theme ID
  3. Open http://127.0.0.1:9292 in the browser
  4. After ~5–6 successful requests, the CLI crashes with the mismatch error

Verbose log (key section)

Sending HEAD request to URL https://[STORE].myshopify.com/?preview_theme_id=[DEV_THEME_ID]&_fd=0&pb=0

Request completed with response headers:
  server-timing: theme;desc="[DEV_THEME_ID]" ← ✅ correct

→ Rendering https://[STORE].myshopify.com/?_fd=0&pb=0...  ← ❌ missing preview_theme_id
← 200
Theme ID mismatch: expected [DEV_THEME_ID] but got [LIVE_THEME_ID]; refreshing session...

The HEAD request with preview_theme_id correctly returns the dev theme in server-timing. The mismatch comes from the subsequent render request which omits preview_theme_id and the storefront falls back to serving the live theme.

Environment

  • Shopify CLI version: 3.93.2
  • OS: macOS
  • Node version: v22.x
  • Shell: zsh

Workaround

Using the preview URL directly (https://[STORE].myshopify.com/?preview_theme_id=[DEV_THEME_ID]) instead of http://127.0.0.1:9292 avoids the crash, but this is not a sustainable workflow.

This appears to be a server-side issue where the storefront renderer does not carry the preview_theme_id context between the HEAD validation request and the actual render request.

2 Likes
3

Not a dev by any means, so I’m probably not able to give to many detailed technical infos but still wanted to add that I’m having the same issue since yesterday.

I’m on version 3.94.3 but tried on a bunch of older versions as well with the same result. It randomly started during a session and after that I wasn’t able to load the preview a single time. “shopify theme dev“ connects correctly at first but when then trying to load 127.0.0.1:9292 it fails with the “theme id mismatch” error.

Despite my limited technical knowledge I can confirm that the theme id it’s getting according to the error message is the id of my live theme instead of my dev theme.

  • OS: Win 10
  • CLI: 3.94.3
  • Nodejs: v22.17.1
1 Like
4

I’m having the same issue today.

1 Like
5

This problem has been going on for 2 weeks now and it doesn’t look like Shopify is going to fix it.:melting_face:

2 Likes
6

I had the same problem today, I had to run shopify auth logout and then re-login and it seemed to fix the issue.

7

I tried this as well multiple times but for me it only helps temporarily. After a logout and re-login I can load the preview but after a few page changes the problem returns.

8

Hi :waving_hand: Not sure yet what caused this issue but could you try this version of the CLI and let us know if it improves the situation? @shopify/cli@0.0.0-snapshot-20260508082501