diff --git a/src/replay/index.ts b/src/replay/index.ts
index 26b6c892..ce1722a0 100644
--- a/src/replay/index.ts
+++ b/src/replay/index.ts
@@ -88,6 +88,7 @@ export class Replayer {
    * @param timeOffset number
    */
   public play(timeOffset = 0) {
+    this.timer.clear();
     this.baselineTime = this.events[0].timestamp + timeOffset;
     const actions = new Array<actionWithDelay>();
     for (const event of this.events) {
@@ -113,7 +114,7 @@ export class Replayer {
     const actions = new Array<actionWithDelay>();
     for (const event of this.events) {
       if (
-        event.timestamp < this.lastPlayedEvent.timestamp ||
+        event.timestamp <= this.lastPlayedEvent.timestamp ||
         event === this.lastPlayedEvent
       ) {
         continue;
diff --git a/test/replayer.test.ts b/test/replayer.test.ts
new file mode 100644
index 00000000..a899352c
--- /dev/null
+++ b/test/replayer.test.ts
@@ -0,0 +1,202 @@
+/* tslint:disable no-string-literal */
+
+import * as fs from 'fs';
+import * as path from 'path';
+import * as puppeteer from 'puppeteer';
+import { expect } from 'chai';
+import {
+  EventType,
+  eventWithTime,
+  IncrementalSource,
+  MouseInteractions,
+} from '../src/types';
+import { Replayer } from '../src';
+
+const now = Date.now();
+
+const events: eventWithTime[] = [
+  {
+    type: EventType.DomContentLoaded,
+    data: {},
+    timestamp: now,
+  },
+  {
+    type: EventType.Load,
+    data: {},
+    timestamp: now + 1000,
+  },
+  {
+    type: EventType.Meta,
+    data: {
+      href: 'http://localhost',
+      width: 1000,
+      height: 800,
+    },
+    timestamp: now + 1000,
+  },
+  {
+    type: EventType.FullSnapshot,
+    data: {
+      node: {
+        type: 0,
+        childNodes: [
+          {
+            type: 2,
+            tagName: 'html',
+            attributes: {},
+            childNodes: [
+              {
+                type: 2,
+                tagName: 'head',
+                attributes: {},
+                childNodes: [],
+                id: 3,
+              },
+              {
+                type: 2,
+                tagName: 'body',
+                attributes: {},
+                childNodes: [],
+                id: 4,
+              },
+            ],
+            id: 2,
+          },
+        ],
+        id: 1,
+      },
+      initialOffset: {
+        top: 0,
+        left: 0,
+      },
+    },
+    timestamp: now + 1000,
+  },
+  {
+    type: EventType.IncrementalSnapshot,
+    data: {
+      source: IncrementalSource.MouseInteraction,
+      type: MouseInteractions.Click,
+      id: 1,
+      x: 0,
+      y: 0,
+    },
+    timestamp: now + 2000,
+  },
+  {
+    type: EventType.IncrementalSnapshot,
+    data: {
+      source: IncrementalSource.MouseInteraction,
+      type: MouseInteractions.Click,
+      id: 1,
+      x: 0,
+      y: 0,
+    },
+    timestamp: now + 3000,
+  },
+  {
+    type: EventType.IncrementalSnapshot,
+    data: {
+      source: IncrementalSource.MouseInteraction,
+      type: MouseInteractions.Click,
+      id: 1,
+      x: 0,
+      y: 0,
+    },
+    timestamp: now + 4000,
+  },
+];
+
+interface IWindow extends Window {
+  rrweb: {
+    Replayer: typeof Replayer;
+  };
+}
+
+describe('replayer', () => {
+  before(async () => {
+    this.browser = await puppeteer.launch({
+      headless: false,
+      args: ['--no-sandbox'],
+    });
+
+    const bundlePath = path.resolve(__dirname, '../dist/rrweb.min.js');
+    this.code = fs.readFileSync(bundlePath, 'utf8');
+  });
+
+  beforeEach(async () => {
+    const page: puppeteer.Page = await this.browser.newPage();
+    await page.goto('about:blank');
+    await page.evaluate(this.code);
+    await page.evaluate(`const events = ${JSON.stringify(events)}`);
+    this.page = page;
+
+    page.on('console', msg => console.log('PAGE LOG:', msg.text()));
+  });
+
+  afterEach(async () => {
+    await this.page.close();
+  });
+
+  after(async () => {
+    await this.browser.close();
+  });
+
+  it('can get meta data', async () => {
+    const meta = await this.page.evaluate(() => {
+      const { Replayer } = (window as IWindow).rrweb;
+      const replayer = new Replayer(events);
+      return replayer.getMetaData();
+    });
+    expect(meta).to.deep.equal({
+      totalTime: events[events.length - 1].timestamp - events[0].timestamp,
+    });
+  });
+
+  it('will start actions when play', async () => {
+    const actionLength = await this.page.evaluate(() => {
+      const { Replayer } = (window as IWindow).rrweb;
+      const replayer = new Replayer(events);
+      replayer.play();
+      return replayer['timer']['actions'].length;
+    });
+    expect(actionLength).to.equal(events.length);
+  });
+
+  it('will clean actions when pause', async () => {
+    const actionLength = await this.page.evaluate(() => {
+      const { Replayer } = (window as IWindow).rrweb;
+      const replayer = new Replayer(events);
+      replayer.play();
+      replayer.pause();
+      return replayer['timer']['actions'].length;
+    });
+    expect(actionLength).to.equal(0);
+  });
+
+  it('can play at any time offset', async () => {
+    const actionLength = await this.page.evaluate(() => {
+      const { Replayer } = (window as IWindow).rrweb;
+      const replayer = new Replayer(events);
+      replayer.play(1500);
+      return replayer['timer']['actions'].length;
+    });
+    expect(actionLength).to.equal(
+      events.filter(e => e.timestamp - events[0].timestamp >= 1500).length,
+    );
+  });
+
+  it('can resume at any time offset', async () => {
+    const actionLength = await this.page.evaluate(() => {
+      const { Replayer } = (window as IWindow).rrweb;
+      const replayer = new Replayer(events);
+      replayer.play(1500);
+      replayer.pause();
+      replayer.resume(1500);
+      return replayer['timer']['actions'].length;
+    });
+    expect(actionLength).to.equal(
+      events.filter(e => e.timestamp - events[0].timestamp >= 1500).length,
+    );
+  });
+});