diff --git a/package.json b/package.json
index 3f778be877..89eb7a25ba 100644
--- a/package.json
+++ b/package.json
@@ -13,6 +13,8 @@
     "build-l10n-prod:quiet": "yarn build:clean && yarn build-photon && cross-env NODE_ENV=production L10N=1 webpack",
     "build-l10n-prod": "yarn build-l10n-prod:quiet --progress",
     "build-photon": "webpack --config res/photon/webpack.config.js",
+    "build-batch-checker": "yarn build-batch-checker:quiet --progress",
+    "build-batch-checker:quiet": "yarn build:clean && cross-env NODE_ENV=production webpack --config src/batch-checker/webpack.config.js",
     "build-symbolicator-cli": "yarn build-symbolicator-cli:quiet --progress",
     "build-symbolicator-cli:quiet": "yarn build:clean && cross-env NODE_ENV=production webpack --config src/symbolicator-cli/webpack.config.js",
     "lint": "node bin/output-fixing-commands.js run-p lint-js lint-css prettier-run",
diff --git a/src/batch-checker/index.js b/src/batch-checker/index.js
new file mode 100644
index 0000000000..0406c3a0ce
--- /dev/null
+++ b/src/batch-checker/index.js
@@ -0,0 +1,178 @@
+// @flow
+
+/**
+ * This implements a simple CLI to check existing public profiles for certain
+ * criteria.
+ *
+ * To use it it first needs to be built:
+ *   yarn build-batch-checker
+ *
+ * Then it can be run from the `dist` directory:
+ *   node dist/batch-checker.js --hashes-file <path to text file>
+ *
+ * For example:
+ *   yarn build-batch-checker && node dist/batch-checker.js --hashes-file ~/Downloads/profile-hashes.txt
+ *
+ */
+
+const fs = require('fs');
+
+import { unserializeProfileOfArbitraryFormat } from '../profile-logic/process-profile';
+import { getProfileUrlForHash } from '../actions/receive-profile';
+import { getTimeRangeIncludingAllThreads } from '../profile-logic/profile-data';
+import { encodeUintSetForUrlComponent } from '../utils/uintarray-encoding';
+
+interface CliOptions {
+  hashesFile: string;
+}
+
+function checkProfileThreadCPUDelta(profile: any, hash: string): Set<string> {
+  const outcomes = new Set();
+  const rootRange = getTimeRangeIncludingAllThreads(profile);
+  const { threads } = profile;
+  for (let threadIndex = 0; threadIndex < threads.length; threadIndex++) {
+    const thread = threads[threadIndex];
+    const threadCPUDelta = thread.samples.threadCPUDelta;
+    if (!threadCPUDelta) {
+      outcomes.add('has thread without threadCPUDelta');
+      continue;
+    }
+
+    outcomes.add('has thread with threadCPUDelta');
+    const len = thread.samples.length;
+    if (len < 2) {
+      outcomes.add('has thread with fewer than two samples');
+      continue;
+    }
+    if (threadCPUDelta[0] === null) {
+      outcomes.add('has null in first threadCPUDelta');
+    }
+    const firstNonNullIndex = threadCPUDelta.findIndex((d) => d !== null);
+    if (firstNonNullIndex !== -1) {
+      for (let i = firstNonNullIndex + 1; i < len; i++) {
+        if (threadCPUDelta[i] === null) {
+          outcomes.add('has null after first null value in threadCPUDelta');
+          const sampleTime = thread.samples.time[i];
+          const relativeSampleTime = sampleTime - rootRange.start;
+          const url = `https://profiler.firefox.com/public/${hash}/?v=10&thread=${encodeUintSetForUrlComponent(new Set([threadIndex]))}`;
+          console.log(
+            `non-null at sample ${i} on thread ${threadIndex} at relative time ${(relativeSampleTime / 1000).toFixed(3)}s: ${url}`
+          );
+          break;
+        }
+      }
+    }
+  }
+  return outcomes;
+}
+
+function checkProfileSchemaMatching(profile: any, _hash: string): Set<string> {
+  const { meta, threads } = profile;
+  const { markerSchema } = meta;
+  const markerSchemaNames = new Set(markerSchema.map((schema) => schema.name));
+  const tracingCategories = new Set();
+  const textNames = new Set();
+
+  const outcomes = new Set();
+  for (let threadIndex = 0; threadIndex < threads.length; threadIndex++) {
+    const thread = threads[threadIndex];
+    const { markers, stringTable } = thread;
+    for (let markerIndex = 0; markerIndex < markers.length; markerIndex++) {
+      const nameIndex = markers.name[markerIndex];
+      const data = markers.data[markerIndex];
+      if (
+        data &&
+        data.type &&
+        data.type === 'tracing' &&
+        data.category &&
+        markerSchemaNames.has(data.category)
+      ) {
+        if (!tracingCategories.has(data.category)) {
+          console.log(
+            `Found tracing marker whose schema is for category ${data.category}, thread index ${threadIndex}, marker index ${markerIndex}`
+          );
+          outcomes.add(
+            `has tracing marker whose schema is for category ${data.category}`
+          );
+          tracingCategories.add(data.category);
+        }
+        continue;
+      }
+      const name = stringTable.getString(nameIndex);
+      if (
+        data &&
+        data.type &&
+        data.type === 'Text' &&
+        markerSchemaNames.has(name)
+      ) {
+        if (!textNames.has(name)) {
+          console.log(
+            `Found Text marker whose schema is for name ${name}, thread index ${threadIndex}, marker index ${markerIndex}`
+          );
+          outcomes.add(`has Text marker whose schema is for name ${name}`);
+          textNames.add(name);
+        }
+        continue;
+      }
+    }
+  }
+
+  return outcomes;
+}
+
+function checkProfile(profile: any, hash: string): Set<string> {
+  return checkProfileSchemaMatching(profile, hash);
+}
+
+export async function run(options: CliOptions) {
+  const hashes = fs.readFileSync(options.hashesFile, 'utf8').split('\n');
+  console.log(`Have ${hashes.length} hashes.`);
+
+  for (let i = 0; i < hashes.length; i++) {
+    const hash = hashes[i];
+    console.log(
+      `Checking profile ${i + 1} of ${hashes.length} with hash ${hash}`
+    );
+    try {
+      const response = await fetch(getProfileUrlForHash(hash));
+      const serializedProfile = await response.json();
+      const profile =
+        await unserializeProfileOfArbitraryFormat(serializedProfile);
+      if (profile === undefined) {
+        throw new Error('Unable to parse the profile.');
+      }
+      const outcome = checkProfile(profile, hash);
+      console.log(`Outcome: ${[...outcome].join(', ')}`);
+    } catch (e) {
+      console.log(`Failed: ${e}`);
+    }
+  }
+
+  console.log('Finished.');
+}
+
+export function makeOptionsFromArgv(processArgv: string[]): CliOptions {
+  const argv = require('minimist')(processArgv.slice(2));
+
+  if (!('hashes-file' in argv && typeof argv['hashes-file'] === 'string')) {
+    throw new Error(
+      'Argument --hashes-file must be supplied with the path to a text file of profile hashes'
+    );
+  }
+
+  return {
+    hashesFile: argv['hashes-file'],
+  };
+}
+
+if (!module.parent) {
+  try {
+    const options = makeOptionsFromArgv(process.argv);
+    run(options).catch((err) => {
+      throw err;
+    });
+  } catch (e) {
+    console.error(e);
+    process.exit(1);
+  }
+}
diff --git a/src/batch-checker/webpack.config.js b/src/batch-checker/webpack.config.js
new file mode 100644
index 0000000000..d0ff0e0449
--- /dev/null
+++ b/src/batch-checker/webpack.config.js
@@ -0,0 +1,32 @@
+// @noflow
+const path = require('path');
+const projectRoot = path.join(__dirname, '../..');
+const includes = [path.join(projectRoot, 'src')];
+
+module.exports = {
+  name: 'batch-checker',
+  target: 'node',
+  mode: process.env.NODE_ENV,
+  output: {
+    path: path.resolve(projectRoot, 'dist'),
+    filename: 'batch-checker.js',
+  },
+  entry: './src/batch-checker/index.js',
+  module: {
+    rules: [
+      {
+        test: /\.js$/,
+        use: ['babel-loader'],
+        include: includes,
+      },
+      {
+        test: /\.svg$/,
+        type: 'asset/resource',
+      },
+    ],
+  },
+  experiments: {
+    // Make WebAssembly work just like in webpack v4
+    syncWebAssembly: true,
+  },
+};