diff --git a/.github/workflows/benchmark.yml b/.github/workflows/benchmark.yml
new file mode 100644
index 000000000..b98d140b1
--- /dev/null
+++ b/.github/workflows/benchmark.yml
@@ -0,0 +1,41 @@
+name: Vercel Deploy Preview
+env:
+  VERCEL_ORG_ID: ${{ secrets.VERCEL_ORG_ID }}
+  VERCEL_PROJECT_ID: ${{ secrets.VERCEL_PROJECT_ID }}
+on:
+  issue_comment:
+    types: [created]
+  push:
+    branches:
+      - perf-test
+jobs:
+  deploy:
+    runs-on: ubuntu-latest
+    # todo skip already created deploys on that commit
+    if: >-
+      github.event.issue.pull_request != '' &&
+      (
+        contains(github.event.comment.body, '/benchmark')
+      )
+    permissions:
+      pull-requests: write
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+        with:
+          ref: refs/pull/${{ github.event.issue.number }}/head
+      - run: npm i -g pnpm@9.0.4
+      - uses: actions/setup-node@v4
+        with:
+          node-version: 18
+          cache: "pnpm"
+      - run: pnpm install
+      - run: pnpm build
+      - run: pnpm test:benchmark
+      # read benchmark results from stdout
+      - run: echo "BENCHMARK_RESULT=$(cat benchmark.txt)" >> $GITHUB_ENV
+      - uses: mshick/add-pr-comment@v2
+        with:
+          allow-repeats: true
+          message: |
+            Benchmark result: ${{ env.BENCHMARK_RESULT }}
diff --git a/cypress.config.ts b/cypress.config.ts
index f9bd94783..7c4098a9f 100644
--- a/cypress.config.ts
+++ b/cypress.config.ts
@@ -1,5 +1,7 @@
 import { defineConfig } from 'cypress'
 
+const isPerformanceTest = process.env.PERFORMANCE_TEST === 'true'
+
 export default defineConfig({
   video: false,
   chromeWebSecurity: false,
@@ -31,7 +33,7 @@ export default defineConfig({
       return require('./cypress/plugins/index.js')(on, config)
     },
     baseUrl: 'http://localhost:8080',
-    specPattern: 'cypress/e2e/**/*.spec.ts',
+    specPattern: !isPerformanceTest ? 'cypress/e2e/**/*.spec.ts' : 'cypress/e2e/rendering_performance.spec.ts',
     excludeSpecPattern: ['**/__snapshots__/*', '**/__image_snapshots__/*'],
   },
 })
diff --git a/cypress/e2e/rendering_performance.spec.ts b/cypress/e2e/rendering_performance.spec.ts
new file mode 100644
index 000000000..4a7390ab5
--- /dev/null
+++ b/cypress/e2e/rendering_performance.spec.ts
@@ -0,0 +1,37 @@
+/// <reference types="cypress" />
+import { BenchmarkAdapter } from '../../src/benchmarkAdapter'
+import { setOptions, cleanVisit, visit } from './shared'
+
+it('Benchmark rendering performance', () => {
+  cleanVisit('/?openBenchmark=true&renderDistance=5')
+  // wait for render end event
+  return cy.document().then({ timeout: 120_000 }, doc => {
+    return new Cypress.Promise(resolve => {
+      cy.log('Waiting for world to load')
+      doc.addEventListener('cypress-world-ready', resolve)
+    }).then(() => {
+      cy.log('World loaded')
+    })
+  }).then(() => {
+    cy.window().then(win => {
+      const adapter = win.benchmarkAdapter as BenchmarkAdapter
+      const renderTimeWorst = adapter.worstRenderTime
+      const renderTimeAvg = adapter.averageRenderTime
+      const fpsWorst = 1000 / renderTimeWorst
+      const fpsAvg = 1000 / renderTimeAvg
+      const totalTime = adapter.worldLoadTime
+
+      const messages = [
+        `Worst FPS: ${fpsWorst.toFixed(2)}`,
+        `Average FPS: ${fpsAvg.toFixed(2)}`,
+        `Total time: ${totalTime.toFixed(2)}s`,
+        `Memory usage average: ${adapter.memoryUsageAverage.toFixed(2)}MB`,
+        `Memory usage worst: ${adapter.memoryUsageWorst.toFixed(2)}MB`,
+      ]
+      for (const message of messages) {
+        cy.log(message)
+      }
+      cy.writeFile('benchmark.txt', messages.join('\n'))
+    })
+  })
+})
diff --git a/package.json b/package.json
index c03422604..f3b68bf49 100644
--- a/package.json
+++ b/package.json
@@ -8,6 +8,7 @@
     "build": "node scripts/build.js copyFiles && node scripts/prepareData.mjs -f && node esbuild.mjs --minify --prod",
     "check-build": "tsc && pnpm build",
     "test:cypress": "cypress run",
+    "test:benchmark": "PERFORMANCE_TEST=true cypress run",
     "test-unit": "vitest",
     "test:e2e": "start-test http-get://localhost:8080 test:cypress",
     "prod-start": "node server.js",
@@ -63,7 +64,7 @@
     "esbuild-plugin-polyfill-node": "^0.3.0",
     "express": "^4.18.2",
     "filesize": "^10.0.12",
-    "flying-squid": "npm:@zardoy/flying-squid@^0.0.29",
+    "flying-squid": "npm:@zardoy/flying-squid@^0.0.32",
     "fs-extra": "^11.1.1",
     "google-drive-browserfs": "github:zardoy/browserfs#google-drive",
     "iconify-icon": "^1.0.8",
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 1f2b48099..a22220966 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -107,8 +107,8 @@ importers:
         specifier: ^10.0.12
         version: 10.0.12
       flying-squid:
-        specifier: npm:@zardoy/flying-squid@^0.0.29
-        version: '@zardoy/flying-squid@0.0.29(encoding@0.1.13)'
+        specifier: npm:@zardoy/flying-squid@^0.0.32
+        version: '@zardoy/flying-squid@0.0.32(encoding@0.1.13)'
       fs-extra:
         specifier: ^11.1.1
         version: 11.1.1
@@ -3078,8 +3078,8 @@ packages:
     resolution: {integrity: sha512-6xm38yGVIa6mKm/DUCF2zFFJhERh/QWp1ufm4cNUvxsONBmfPg8uZ9pZBdOmF6qFGr/HlT6ABBkCSx/dlEtvWg==}
     engines: {node: '>=12 <14 || 14.2 - 14.9 || >14.10.0'}
 
-  '@zardoy/flying-squid@0.0.29':
-    resolution: {integrity: sha512-E5Nk1gMeH+fAHM5aJY8kIxjBS/zuPtPD6QPeZg+laPV5H58Jx3Et17clF1zC9MT2wyFQ5wi5uTnfdGBTpSEqHw==}
+  '@zardoy/flying-squid@0.0.32':
+    resolution: {integrity: sha512-Ifj8XrnsE3j3+lCeyUQ426LzsOzU/Z+qKG+aZNf90VstBhCvjmVAOmG7J5N74ivvujx+x6eXCgjjw6gcd/XKNQ==}
     engines: {node: '>=8'}
     hasBin: true
 
@@ -6750,6 +6750,11 @@ packages:
     version: 1.35.0
     engines: {node: '>=14'}
 
+  prismarine-chunk@https://codeload.github.com/zardoy/prismarine-chunk/tar.gz/cea0b6c792d7dcbb69dfd20fa48be5fd60ce83ef:
+    resolution: {tarball: https://codeload.github.com/zardoy/prismarine-chunk/tar.gz/cea0b6c792d7dcbb69dfd20fa48be5fd60ce83ef}
+    version: 1.35.0
+    engines: {node: '>=14'}
+
   prismarine-entity@2.3.1:
     resolution: {integrity: sha512-HOv8l7IetHNf4hwZ7V/W4vM3GNl+e6VCtKDkH9h02TRq7jWngsggKtJV+VanCce/sNwtJUhJDjORGs728ep4MA==}
 
@@ -11974,7 +11979,7 @@ snapshots:
       '@types/emscripten': 1.39.8
       tslib: 1.14.1
 
-  '@zardoy/flying-squid@0.0.29(encoding@0.1.13)':
+  '@zardoy/flying-squid@0.0.32(encoding@0.1.13)':
     dependencies:
       '@tootallnate/once': 2.0.0
       change-case: 4.1.2
@@ -11989,7 +11994,7 @@ snapshots:
       mkdirp: 2.1.6
       node-gzip: 1.1.2
       node-rsa: 1.1.1
-      prismarine-chunk: https://codeload.github.com/zardoy/prismarine-chunk/tar.gz/9662306deea57d8d0ba0a2a3f3f7adb95f0131e3(minecraft-data@3.65.0)
+      prismarine-chunk: https://codeload.github.com/zardoy/prismarine-chunk/tar.gz/cea0b6c792d7dcbb69dfd20fa48be5fd60ce83ef(minecraft-data@3.65.0)
       prismarine-entity: 2.3.1
       prismarine-item: 1.14.0
       prismarine-nbt: 2.5.0
@@ -12000,6 +12005,7 @@ snapshots:
       random-seed: 0.3.0
       range: 0.0.3
       readline: 1.3.0
+      sanitize-filename: 1.6.3
       typed-emitter: 1.4.0
       uuid-1345: 1.0.2
       vec3: 0.1.8
@@ -13263,7 +13269,7 @@ snapshots:
   diamond-square@https://codeload.github.com/zardoy/diamond-square/tar.gz/4bbe28dcad35403abaa925055e91f601a61b9015:
     dependencies:
       minecraft-data: 3.65.0
-      prismarine-chunk: https://codeload.github.com/zardoy/prismarine-chunk/tar.gz/9662306deea57d8d0ba0a2a3f3f7adb95f0131e3(minecraft-data@3.65.0)
+      prismarine-chunk: https://codeload.github.com/zardoy/prismarine-chunk/tar.gz/cea0b6c792d7dcbb69dfd20fa48be5fd60ce83ef(minecraft-data@3.65.0)
       prismarine-registry: 1.7.0
       random-seed: 0.3.0
       vec3: 0.1.8
@@ -16592,6 +16598,19 @@ snapshots:
     transitivePeerDependencies:
       - minecraft-data
 
+  prismarine-chunk@https://codeload.github.com/zardoy/prismarine-chunk/tar.gz/cea0b6c792d7dcbb69dfd20fa48be5fd60ce83ef(minecraft-data@3.65.0):
+    dependencies:
+      prismarine-biome: 1.3.0(minecraft-data@3.65.0)(prismarine-registry@1.7.0)
+      prismarine-block: https://codeload.github.com/zardoy/prismarine-block/tar.gz/dd4954fff3b334f8ce063d18e39b2e9414ece5b8
+      prismarine-nbt: 2.5.0
+      prismarine-registry: 1.7.0
+      smart-buffer: 4.2.0
+      uint4: 0.1.2
+      vec3: 0.1.8
+      xxhash-wasm: 0.4.2
+    transitivePeerDependencies:
+      - minecraft-data
+
   prismarine-entity@2.3.1:
     dependencies:
       prismarine-chat: 1.10.1
diff --git a/prismarine-viewer/viewer/lib/viewerWrapper.ts b/prismarine-viewer/viewer/lib/viewerWrapper.ts
index 57317f422..3b042f4a6 100644
--- a/prismarine-viewer/viewer/lib/viewerWrapper.ts
+++ b/prismarine-viewer/viewer/lib/viewerWrapper.ts
@@ -52,9 +52,11 @@ export class ViewerWrapper {
     windowFocused = true
     trackWindowFocus () {
         window.addEventListener('focus', () => {
+            console.log('window focused')
             this.windowFocused = true
         })
         window.addEventListener('blur', () => {
+            console.log('window blurred')
             this.windowFocused = false
         })
     }
diff --git a/prismarine-viewer/viewer/lib/worldrendererThree.ts b/prismarine-viewer/viewer/lib/worldrendererThree.ts
index cc89a8238..9f5b94b53 100644
--- a/prismarine-viewer/viewer/lib/worldrendererThree.ts
+++ b/prismarine-viewer/viewer/lib/worldrendererThree.ts
@@ -17,6 +17,8 @@ export class WorldRendererThree extends WorldRendererCommon {
     signsCache = new Map<string, any>()
     starField: StarField
     cameraSectionPos: Vec3 = new Vec3(0, 0, 0)
+    worstRenderTime = 0
+    avgRenderTime = 0
 
     get tilesRendered () {
         return Object.values(this.sectionObjects).reduce((acc, obj) => acc + (obj as any).tilesCount, 0)
@@ -72,20 +74,6 @@ export class WorldRendererThree extends WorldRendererCommon {
         const chunkCoords = data.key.split(',')
         if (!this.loadedChunks[chunkCoords[0] + ',' + chunkCoords[2]] || !data.geometry.positions.length || !this.active) return
 
-        // if (!this.initialChunksLoad && this.enableChunksLoadDelay) {
-        //   const newPromise = new Promise(resolve => {
-        //     if (this.droppedFpsPercentage > 0.5) {
-        //       setTimeout(resolve, 1000 / 50 * this.droppedFpsPercentage)
-        //     } else {
-        //       setTimeout(resolve)
-        //     }
-        //   })
-        //   this.promisesQueue.push(newPromise)
-        //   for (const promise of this.promisesQueue) {
-        //     await promise
-        //   }
-        // }
-
         const geometry = new THREE.BufferGeometry()
         geometry.setAttribute('position', new THREE.BufferAttribute(data.geometry.positions, 3))
         geometry.setAttribute('normal', new THREE.BufferAttribute(data.geometry.normals, 3))
@@ -163,7 +151,11 @@ export class WorldRendererThree extends WorldRendererCommon {
     render () {
         tweenJs.update()
         const cam = this.camera instanceof THREE.Group ? this.camera.children.find(child => child instanceof THREE.PerspectiveCamera) as THREE.PerspectiveCamera : this.camera
+        const start = performance.now()
         this.renderer.render(this.scene, cam)
+        const totalTime = performance.now() - start
+        this.avgRenderTime = this.avgRenderTime * 0.9 + totalTime * 0.1 // exponential moving average
+        this.worstRenderTime = Math.max(this.worstRenderTime, totalTime)
     }
 
     renderSign (position: Vec3, rotation: number, isWall: boolean, isHanging: boolean, blockEntity) {
diff --git a/src/benchmark.ts b/src/benchmark.ts
new file mode 100644
index 000000000..a9a342d61
--- /dev/null
+++ b/src/benchmark.ts
@@ -0,0 +1,73 @@
+import { Vec3 } from 'vec3'
+import { downloadAndOpenFileFromUrl } from './downloadAndOpenFile'
+import { activeModalStack, miscUiState } from './globalState'
+import { options } from './optionsStorage'
+import { BenchmarkAdapter } from './benchmarkAdapter'
+
+const testWorldFixtureUrl = 'https://bucket.mcraft.fun/Future CITY 4.4-slim.zip'
+const testWorldFixtureSpawn = [-133, 87, 309] as const
+
+export const openBenchmark = async (renderDistance = 8) => {
+  let memoryUsageAverage = 0
+  let memoryUsageSamples = 0
+  let memoryUsageWorst = 0
+  setInterval(() => {
+    const memoryUsage = (window.performance as any)?.memory?.usedJSHeapSize
+    if (memoryUsage) {
+      memoryUsageAverage = (memoryUsageAverage * memoryUsageSamples + memoryUsage) / (memoryUsageSamples + 1)
+      memoryUsageSamples++
+      if (memoryUsage > memoryUsageWorst) {
+        memoryUsageWorst = memoryUsage
+      }
+    }
+  }, 200)
+
+  const benchmarkAdapter: BenchmarkAdapter = {
+    get worldLoadTime () {
+      return window.worldLoadTime
+    },
+    get averageRenderTime () {
+      return window.viewer.world.avgRenderTime
+    },
+    get worstRenderTime () {
+      return window.viewer.world.worstRenderTime
+    },
+    get memoryUsageAverage () {
+      return memoryUsageAverage
+    },
+    get memoryUsageWorst () {
+      return memoryUsageWorst
+    }
+  }
+  window.benchmarkAdapter = benchmarkAdapter
+
+  options.renderDistance = renderDistance
+  void downloadAndOpenFileFromUrl(testWorldFixtureUrl, undefined, {
+    connectEvents: {
+      serverCreated () {
+        if (testWorldFixtureSpawn) {
+          localServer!.spawnPoint = new Vec3(...testWorldFixtureSpawn)
+          localServer!.on('newPlayer', (player) => {
+            player.on('dataLoaded', () => {
+              player.position = new Vec3(...testWorldFixtureSpawn)
+            })
+          })
+        }
+      },
+    }
+  })
+}
+
+export const registerOpenBenchmarkListener = () => {
+  const params = new URLSearchParams(window.location.search)
+  if (params.get('openBenchmark')) {
+    void openBenchmark(params.has('renderDistance') ? +params.get('renderDistance')! : undefined)
+  }
+
+  window.addEventListener('keydown', (e) => {
+    if (e.code === 'KeyB' && e.shiftKey && !miscUiState.gameLoaded && activeModalStack.length === 0) {
+      e.preventDefault()
+      void openBenchmark()
+    }
+  })
+}
diff --git a/src/benchmarkAdapter.ts b/src/benchmarkAdapter.ts
new file mode 100644
index 000000000..9eef1121c
--- /dev/null
+++ b/src/benchmarkAdapter.ts
@@ -0,0 +1,7 @@
+export interface BenchmarkAdapter {
+    worldLoadTime: number
+    averageRenderTime: number
+    worstRenderTime: number
+    memoryUsageAverage: number
+    memoryUsageWorst: number
+}
diff --git a/src/browserfs.ts b/src/browserfs.ts
index ebe8acfdd..aa2c0e9e9 100644
--- a/src/browserfs.ts
+++ b/src/browserfs.ts
@@ -10,6 +10,7 @@ import { fsState, loadSave } from './loadSave'
 import { installTexturePack, installTexturePackFromHandle, updateTexturePackInstalledState } from './texturePack'
 import { miscUiState } from './globalState'
 import { setLoadingScreenStatus } from './utils'
+import { ConnectOptions } from './connect'
 const { GoogleDriveFileSystem } = require('google-drive-browserfs/src/backends/GoogleDrive') // disable type checking
 
 browserfs.install(window)
@@ -434,7 +435,7 @@ export const copyFilesAsync = async (pathSrc: string, pathDest: string, fileCopi
 }
 
 // todo rename method
-const openWorldZipInner = async (file: File | ArrayBuffer, name = file['name']) => {
+const openWorldZipInner = async (file: File | ArrayBuffer, name = file['name'], connectOptions?: Partial<ConnectOptions>) => {
   await new Promise<void>(async resolve => {
     browserfs.configure({
       // todo
@@ -478,7 +479,7 @@ const openWorldZipInner = async (file: File | ArrayBuffer, name = file['name'])
     }
 
     if (availableWorlds.length === 1) {
-      await loadSave(`/world/${availableWorlds[0]}`)
+      await loadSave(`/world/${availableWorlds[0]}`, connectOptions)
       return
     }
 
diff --git a/src/connect.ts b/src/connect.ts
index 5e4df8599..fc716c843 100644
--- a/src/connect.ts
+++ b/src/connect.ts
@@ -1,15 +1,24 @@
 export type ConnectOptions = {
-  server?: string;
-  singleplayer?: any;
-  username: string;
-  password?: any;
-  proxy?: any;
-  botVersion?: any;
-  serverOverrides?;
-  serverOverridesFlat?;
-  peerId?: string;
-  ignoreQs?: boolean;
+  server?: string
+  singleplayer?: any
+  username: string
+  password?: any
+  proxy?: any
+  botVersion?: any
+  serverOverrides?
+  serverOverridesFlat?
+  peerId?: string
+  ignoreQs?: boolean
   onSuccessfulPlay?: () => void
   autoLoginPassword?: string
   serverIndex?: string
+
+  connectEvents?: {
+    serverCreated?: () => void
+    // connect: () => void;
+    // disconnect: () => void;
+    // error: (err: any) => void;
+    // ready: () => void;
+    // end: () => void;
+  }
 }
diff --git a/src/downloadAndOpenFile.ts b/src/downloadAndOpenFile.ts
index 7ac154fcb..ad0f831c4 100644
--- a/src/downloadAndOpenFile.ts
+++ b/src/downloadAndOpenFile.ts
@@ -2,27 +2,25 @@ import prettyBytes from 'pretty-bytes'
 import { openWorldZip } from './browserfs'
 import { getResourcePackName, installTexturePack, resourcePackState, updateTexturePackInstalledState } from './texturePack'
 import { setLoadingScreenStatus } from './utils'
+import { ConnectOptions } from './connect'
 
 export const getFixedFilesize = (bytes: number) => {
   return prettyBytes(bytes, { minimumFractionDigits: 2, maximumFractionDigits: 2 })
 }
 
-const inner = async () => {
-  const qs = new URLSearchParams(window.location.search)
-  let mapUrl = qs.get('map')
-  const texturepack = qs.get('texturepack')
+export const downloadAndOpenFileFromUrl = async (mapUrl: string | undefined, texturepackUrl: string | undefined, connectOptions?: Partial<ConnectOptions>) => {
   // fixme
-  if (texturepack) mapUrl = texturepack
+  if (texturepackUrl) mapUrl = texturepackUrl
   if (!mapUrl) return false
 
-  if (texturepack) {
+  if (texturepackUrl) {
     await updateTexturePackInstalledState()
     if (resourcePackState.resourcePackInstalled) {
       if (!confirm(`You are going to install a new resource pack, which will REPLACE the current one: ${await getResourcePackName()} Continue?`)) return
     }
   }
   const name = mapUrl.slice(mapUrl.lastIndexOf('/') + 1).slice(-25)
-  const downloadThing = texturepack ? 'texturepack' : 'world'
+  const downloadThing = texturepackUrl ? 'texturepack' : 'world'
   setLoadingScreenStatus(`Downloading ${downloadThing} ${name}...`)
 
   const response = await fetch(mapUrl)
@@ -63,17 +61,20 @@ const inner = async () => {
       },
     })
   ).arrayBuffer()
-  if (texturepack) {
+  if (texturepackUrl) {
     const name = mapUrl.slice(mapUrl.lastIndexOf('/') + 1).slice(-30)
     await installTexturePack(buffer, name)
   } else {
-    await openWorldZip(buffer)
+    await openWorldZip(buffer, undefined, connectOptions)
   }
 }
 
 export default async () => {
   try {
-    return await inner()
+    const qs = new URLSearchParams(window.location.search)
+    const mapUrl = qs.get('map')
+    const texturepack = qs.get('texturepack')
+    return await downloadAndOpenFileFromUrl(mapUrl ?? undefined, texturepack ?? undefined)
   } catch (err) {
     setLoadingScreenStatus(`Failed to download. Either refresh page or remove map param from URL. Reason: ${err.message}`)
     return true
diff --git a/src/index.ts b/src/index.ts
index 72f270d42..4c667c6fe 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -42,6 +42,7 @@ import debug from 'debug'
 import { defaultsDeep } from 'lodash-es'
 
 import { initVR } from './vr'
+import { registerOpenBenchmarkListener } from './benchmark'
 import {
   AppConfig,
   activeModalStack,
@@ -218,8 +219,14 @@ function hideCurrentScreens () {
   insertActiveModalStack('', [])
 }
 
-const loadSingleplayer = (serverOverrides = {}, flattenedServerOverrides = {}) => {
-  void connect({ singleplayer: true, username: options.localUsername, password: '', serverOverrides, serverOverridesFlat: flattenedServerOverrides })
+const loadSingleplayer = (serverOverrides = {}, flattenedServerOverrides = {}, otherOptions: Partial<ConnectOptions> = {}) => {
+  void connect({
+    singleplayer: true,
+    username: options.localUsername,
+    serverOverrides,
+    serverOverridesFlat: flattenedServerOverrides,
+    ...otherOptions
+  })
 }
 function listenGlobalEvents () {
   window.addEventListener('connect', e => {
@@ -227,7 +234,9 @@ function listenGlobalEvents () {
     void connect(options)
   })
   window.addEventListener('singleplayer', (e) => {
-    loadSingleplayer((e as CustomEvent).detail)
+    const { detail } = (e as CustomEvent)
+    const { connectOptions, ...rest } = detail
+    loadSingleplayer(rest, {}, connectOptions)
   })
 }
 
@@ -406,6 +415,7 @@ async function connect (connectOptions: ConnectOptions) {
 
       setLoadingScreenStatus('Starting local server')
       localServer = window.localServer = window.server = startLocalServer(serverOptions)
+      connectOptions?.connectEvents?.serverCreated?.()
       // todo need just to call quit if started
       // loadingScreen.maybeRecoverable = false
       // init world, todo: do it for any async plugins
@@ -578,6 +588,7 @@ async function connect (connectOptions: ConnectOptions) {
   const spawnEarlier = !singleplayer && !p2pMultiplayer
   // don't use spawn event, player can be dead
   bot.once(spawnEarlier ? 'forcedMove' : 'health', () => {
+    window.worldStartLoad = Date.now()
     errorAbortController.abort()
     const mcData = MinecraftData(bot.version)
     window.PrismarineBlock = PrismarineBlock(mcData.version.minecraftVersion!)
@@ -805,7 +816,9 @@ async function connect (connectOptions: ConnectOptions) {
       // todo might not emit as servers simply don't send chunk if it's empty
       if (!viewer.world.allChunksFinished || done) return
       done = true
-      console.log('All done and ready! In', (Date.now() - start) / 1000, 's')
+      const worldLoadTime = (Date.now() - start) / 1000
+      window.worldLoadTime = worldLoadTime
+      console.log('All done and ready! In', worldLoadTime, 's')
       viewer.render() // ensure the last state is rendered
       document.dispatchEvent(new Event('cypress-world-ready'))
     })
@@ -944,7 +957,7 @@ downloadAndOpenFile().then((downloadAction) => {
   })
 }, (err) => {
   console.error(err)
-  alert(`Failed to download file: ${err}`)
+  alert(`Somethin went wrong: ${err}`)
 })
 
 // eslint-disable-next-line @typescript-eslint/no-unnecessary-type-assertion
@@ -956,3 +969,4 @@ if (initialLoader) {
 window.pageLoaded = true
 
 void possiblyHandleStateVariable()
+registerOpenBenchmarkListener()
diff --git a/src/loadSave.ts b/src/loadSave.ts
index 7ca454ff6..5f3241df1 100644
--- a/src/loadSave.ts
+++ b/src/loadSave.ts
@@ -11,6 +11,7 @@ import { isMajorVersionGreater } from './utils'
 
 import { activeModalStacks, insertActiveModalStack, miscUiState } from './globalState'
 import supportedVersions from './supportedVersions.mjs'
+import { ConnectOptions } from './connect'
 
 // todo include name of opened handle (zip)!
 // additional fs metadata
@@ -46,7 +47,7 @@ export const readLevelDat = async (path) => {
   return { levelDat, dataRaw: parsed.value.Data!.value as Record<string, any> }
 }
 
-export const loadSave = async (root = '/world') => {
+export const loadSave = async (root = '/world', connectOptions?: Partial<ConnectOptions>) => {
   // todo test
   if (miscUiState.gameLoaded) {
     await disconnect()
@@ -189,7 +190,8 @@ export const loadSave = async (root = '/world') => {
       } : {},
       ...root === '/world' ? {} : {
         'worldFolder': root
-      }
+      },
+      connectOptions
     },
   }))
 }