diff --git a/src/client/preview.test.ts b/src/client/preview.test.ts
index 66e6377..73076f2 100644
--- a/src/client/preview.test.ts
+++ b/src/client/preview.test.ts
@@ -20,8 +20,11 @@ describe("Preview environment detection", () => {
     delete process.env.GITHUB_REF_NAME;
     delete process.env.CI_COMMIT_BRANCH;
     delete process.env.CIRCLE_BRANCH;
+    delete process.env.CIRCLE_PULL_REQUEST;
     delete process.env.BUILD_SOURCEBRANCHNAME;
+    delete process.env.SYSTEM_PULLREQUEST_PULLREQUESTID;
     delete process.env.BITBUCKET_BRANCH;
+    delete process.env.BITBUCKET_PR_ID;
     delete process.env.TINYBIRD_BRANCH_NAME;
     delete process.env.TINYBIRD_BRANCH_TOKEN;
     delete process.env.TINYBIRD_TOKEN;
@@ -70,6 +73,36 @@ describe("Preview environment detection", () => {
       process.env.CI = "true";
       expect(isPreviewEnvironment()).toBe(false);
     });
+
+    it("returns true for CircleCI pull requests", () => {
+      process.env.CIRCLE_PULL_REQUEST = "https://github.com/org/repo/pull/1";
+      expect(isPreviewEnvironment()).toBe(true);
+    });
+
+    it("returns false for CircleCI builds without a pull request", () => {
+      process.env.CIRCLE_BRANCH = "feature-branch";
+      expect(isPreviewEnvironment()).toBe(false);
+    });
+
+    it("returns true for Azure DevOps pull requests", () => {
+      process.env.SYSTEM_PULLREQUEST_PULLREQUESTID = "42";
+      expect(isPreviewEnvironment()).toBe(true);
+    });
+
+    it("returns false for Azure DevOps builds without a pull request", () => {
+      process.env.BUILD_SOURCEBRANCHNAME = "feature-branch";
+      expect(isPreviewEnvironment()).toBe(false);
+    });
+
+    it("returns true for Bitbucket Pipelines pull requests", () => {
+      process.env.BITBUCKET_PR_ID = "7";
+      expect(isPreviewEnvironment()).toBe(true);
+    });
+
+    it("returns false for Bitbucket Pipelines builds without a pull request", () => {
+      process.env.BITBUCKET_BRANCH = "feature-branch";
+      expect(isPreviewEnvironment()).toBe(false);
+    });
   });
 
   describe("getPreviewBranchName", () => {
diff --git a/src/client/preview.ts b/src/client/preview.ts
index 048956e..330b58c 100644
--- a/src/client/preview.ts
+++ b/src/client/preview.ts
@@ -25,6 +25,9 @@ let cachedBranchName: string | null = null;
 
 /**
  * Detect if we're running in a preview/CI environment
+ *
+ * Recognizes Vercel, GitHub Actions, GitLab, CircleCI, Azure DevOps,
+ * Bitbucket Pipelines, and generic CI (with an explicit preview flag).
  */
 export function isPreviewEnvironment(): boolean {
   return !!(
@@ -34,6 +37,12 @@ export function isPreviewEnvironment(): boolean {
     process.env.GITHUB_HEAD_REF ||
     // GitLab CI (merge requests)
     process.env.CI_MERGE_REQUEST_SOURCE_BRANCH_NAME ||
+    // CircleCI (PRs)
+    process.env.CIRCLE_PULL_REQUEST ||
+    // Azure Pipelines (PRs)
+    process.env.SYSTEM_PULLREQUEST_PULLREQUESTID ||
+    // Bitbucket Pipelines (PRs)
+    process.env.BITBUCKET_PR_ID ||
     // Generic CI with preview indicator
     (process.env.CI && process.env.TINYBIRD_PREVIEW_MODE === "true")
   );