Speed Kit on Shopify: Setup and Behavior

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Key Takeaways

• Secure Crawler Access: Generate a Crawler Access Signature in your Shopify admin panel and paste it into the Speed Kit dashboard to authorize dynamic caching and content synchronization.
• 90-Day Renewal Cycle: Shopify signatures expire after 90 days. Set a calendar reminder to renew on time — an expired signature causes stale cached pages and increased error rates.
• Platform-Aware Configuration: Speed Kit automatically adapts to Shopify's preview mode, rate limits, and query parameter handling — no manual configuration required.

Introduction

To deliver always-fresh content on your Shopify store, Speed Kit regularly fetches your pages in the background using Shopify's Crawler Access Signature — a secure authentication token you generate in your Shopify admin panel. This guide walks you through generating and entering that signature, explains the Shopify-specific settings Speed Kit applies automatically, and covers the renewal steps to keep your store running at peak performance.

Set Up Crawler Access

Shopify enforces bot protection on all storefronts, so Speed Kit's background requests must be authenticated with a Crawler Access Signature. Without a valid signature, Shopify may rate-limit or block Speed Kit's requests, resulting in stale content or error codes.

You can read more about this on the official Shopify help page: Crawling Your Store

Part 1: Generate the Signature in Shopify

1. In your Shopify admin panel, go to Online Store and click on Preferences.

2. Scroll down to the Crawler access section and click the Create signature button.

3. In the "Create new signature" pop-up:

• Set a signature name, for example, "Speed Kit."
• For the Expires in field, select the longest available option, which is typically 90 days. 

This maximizes the time before you need to renew the signature.

4. Click Create signature.

5. A new "Signature fields" pop-up appears with three values you need to copy: Signature, Signature-Input, and Signature-Agent.

6. Copy each of these three values separately.

Part 2: Enter the Signature in the Speed Kit Dashboard

1. Navigate to the Speed Kit App in your Shopify admin panel.

2. Go to the Configs section.

3. Paste the three values you copied from Shopify into the corresponding fields under Configure Crawler Access Signature:

• Signature
• Signature-Input
• Signature-Agent (this should typically read "https://shopify.com" for a Shopify store)

4. Click the Save button to apply the changes.

Shopify-Specific Configuration Details

Speed Kit automatically adapts its configuration to Shopify's platform constraints. No manual configuration is needed for the items below, but understanding them helps with debugging and support conversations. For a full reference of all configuration options, see our documentation: "Speed Kit Configuration."

Preview Mode Handling

When you preview a theme in your Shopify admin, Speed Kit automatically detects the preview cookies (preview_theme and speedkit-shopify-preview) and URL parameters (?preview_theme). Pages accessed in preview mode bypass the cache entirely, ensuring you always see your latest theme changes in real time.

Rate Limit Management

Shopify enforces strict rate limits on all server requests. Speed Kit respects these limits by defaulting to a maximum of 5 requests per second to your Shopify origin, compared to higher defaults on other platforms. This prevents HTTP 429 (Too Many Requests) errors. During periods of high request volume, Speed Kit's dynamic throttling automatically backs off further to protect your store's availability. Customers continue receiving cached content during any throttling — they experience no downtime.

Query Parameter Handling

Shopify appends various tracking and internal query parameters to URLs. Speed Kit automatically strips these before caching to prevent unnecessary cache fragmentation (where the same page gets stored multiple times under different URLs):

• Shopify internal parameters: _fid, _pos, _psq, _sid, _ss, _v.
• Recommendation tracking: Parameters with the pr_ prefix (Shopify product recommendation tracking).
• A/B testing and preview: _ab, _fd, view.

This means two URLs differing only in these parameters correctly resolve to the same cached page.

Console Messages from Shopify's Service Worker

When Speed Kit is active, you may notice many "fetch event block" log messages in your browser's developer console, as shown in the screenshot below. These messages do not come from Speed Kit. Shopify's own interim service worker generates them, logging a message for every resource it processes. These logs are purely informational and do not indicate any problem with Speed Kit or your store. They can be safely ignored, even though they appear frequently.

Keeping Your Setup Current

Signature Renewal

The crawler access signature expires after the duration you selected during setup (typically 90 days). When it expires, Speed Kit loses authorization to fetch fresh content from your store, which can lead to stale cached pages or increased error rates. To renew, repeat the same process from the Installation Guide: generate a new signature in your Shopify admin panel and paste the updated values into the Speed Kit dashboard.

Set a calendar reminder a few days before your current signature expires to avoid any lapse in service. For broader guidance on when configuration updates are needed, see our documentation: "Ensuring Seamless Performance: When to Update Your Speed Kit Configuration."

Verifying Your Setup

You can verify that Speed Kit is correctly installed and running on your Shopify store at any time using the Speed Kit Chrome extension. Open your store in Chrome, click the extension icon, and check the installation status panel. Blue checkmarks next to each requirement confirm a correct setup. If any issue is detected, address it in the Speed Kit app within your Shopify admin — installation is managed there, not in the Chrome extension.