diff --git a/packages/opal-web/src/lib/core/import.ts b/packages/opal-web/src/lib/core/import.ts
index 68baa6d..799ae4c 100644
--- a/packages/opal-web/src/lib/core/import.ts
+++ b/packages/opal-web/src/lib/core/import.ts
@@ -5,7 +5,7 @@
 
 import type { Agent } from '@atproto/api';
 import type { Platform, MicroblogPost, ConvertResult } from '@ewanc26/opal';
-import { convertTwitter, convertMastodon, convertThreads, convertNostr, publishRecords, splitToThread } from '@ewanc26/opal';
+import { convertData, parseTwitterArchive, publishRecords } from '@ewanc26/opal';
 
 export interface ImportResult {
   success: number;
@@ -28,32 +28,11 @@ export async function parseExport(
   platform: Platform,
 ): Promise<ConvertResult> {
   const text = await file.text();
-  let data: unknown;
+  const data = platform === 'twitter'
+    ? parseTwitterArchive(text)
+    : JSON.parse(text);
 
-  if (platform === 'twitter') {
-    const match = text.match(/\[[\s\S]*\]/);
-    if (!match) throw new Error('Could not extract tweet array from Twitter archive');
-    data = JSON.parse(match[0]);
-  } else {
-    data = JSON.parse(text);
-  }
-
-  const parsers: Record<Platform, (data: unknown) => ConvertResult> = {
-    twitter: convertTwitter,
-    mastodon: convertMastodon,
-    threads: convertThreads,
-    nostr: convertNostr,
-  };
-
-  const result = parsers[platform](data);
-
-  // Split long posts into threads
-  const posts: MicroblogPost[] = [];
-  for (const post of result.posts) {
-    posts.push(...splitToThread(post));
-  }
-
-  return { posts, skipped: result.skipped, errors: result.errors };
+  return convertData(platform, data);
 }
 
 /**
diff --git a/packages/opal/src/cli.ts b/packages/opal/src/cli.ts
index 65f9d93..fcb3621 100644
--- a/packages/opal/src/cli.ts
+++ b/packages/opal/src/cli.ts
@@ -6,8 +6,8 @@
  */
 
 import { resolve } from 'node:path';
-import { writeFile } from 'node:fs/promises';
-import { convert } from './convert.js';
+import { readFile, writeFile } from 'node:fs/promises';
+import { convertData, parseTwitterArchive } from './convert.js';
 import type { ConvertOptions, Platform } from './types.js';
 
 const VALID_SOURCES: Platform[] = ['twitter', 'mastodon', 'threads', 'nostr'];
@@ -44,9 +44,9 @@ Usage:
 
 Platforms:
   twitter    Twitter/X archive (tweets.js)
-  mastodon  Mastodon outbox (outbox.json)
-  threads   Threads export (JSON)
-  nostr     Nostr events (JSON array)
+  mastodon   Mastodon outbox (outbox.json)
+  threads    Threads export (JSON)
+  nostr      Nostr events (JSON array)
 
 Options:
   --source <platform>  Source platform (required)
@@ -93,7 +93,13 @@ export async function runCLI(): Promise<void> {
   console.log(`Opal — converting ${opts.source} export…`);
   console.log(`  Input:  ${opts.input}`);
 
-  const result = await convert(opts);
+  // Read and parse the input file
+  const raw = await readFile(opts.input, 'utf-8');
+  const data = opts.source === 'twitter'
+    ? parseTwitterArchive(raw)
+    : JSON.parse(raw);
+
+  const result = convertData(opts.source, data);
 
   console.log(`  Posts:   ${result.posts.length}`);
   console.log(`  Skipped: ${result.skipped}`);
diff --git a/packages/opal/src/convert.ts b/packages/opal/src/convert.ts
index 621c48f..c5ee8f8 100644
--- a/packages/opal/src/convert.ts
+++ b/packages/opal/src/convert.ts
@@ -1,10 +1,11 @@
 /**
- * Main conversion dispatcher — reads input, delegates to the correct
- * platform parser, and runs post-processing (thread splitting).
+ * Main conversion dispatcher — delegates to the correct platform parser
+ * and runs post-processing (thread splitting).
+ *
+ * This module has no Node.js dependencies and is safe for browser use.
  */
 
-import { readFile } from 'node:fs/promises';
-import type { ConvertOptions, ConvertResult, MicroblogPost, Platform } from './types.js';
+import type { ConvertResult, MicroblogPost, Platform } from './types.js';
 import { convertTwitter } from './twitter.js';
 import { convertMastodon } from './mastodon.js';
 import { convertThreads } from './threads.js';
@@ -19,16 +20,16 @@ const parsers: Record<Platform, (data: unknown) => ConvertResult> = {
 };
 
 /**
- * Parse a platform export file and convert to normalised MicroblogPost[].
+ * Convert pre-parsed platform data to normalised MicroblogPost[].
  * Long posts (>300 graphemes) are automatically split into Bluesky threads.
+ *
+ * For Twitter archives, the caller must extract the JSON array from the
+ * JS wrapper before passing it here. Use `parseTwitterArchive()` from
+ * the CLI module for that.
  */
-export async function convert(opts: ConvertOptions): Promise<ConvertResult> {
-  const raw = await readFile(opts.input, 'utf-8');
-  const data = parseRaw(raw, opts.source);
-  const parser = parsers[opts.source];
+export function convertData(source: Platform, data: unknown): ConvertResult {
+  const parser = parsers[source];
   const result = parser(data);
-
-  // Split long posts into threads
   return splitLongPosts(result);
 }
 
@@ -51,21 +52,16 @@ function splitLongPosts(result: ConvertResult): ConvertResult {
 }
 
 /**
- * Pre-process raw file content before passing to the parser.
+ * Pre-process raw Twitter archive content.
  * Twitter archives wrap data in `window.YTD.tweets.part0 = [...]`
  * which isn't valid JSON on its own.
  */
-function parseRaw(raw: string, source: Platform): unknown {
-  if (source === 'twitter') {
-    // Twitter archives assign to a JS variable — extract the JSON array
-    const match = raw.match(/\[[\s\S]*\]/);
-    if (!match) {
-      throw new Error('Could not extract tweet array from Twitter archive file');
-    }
-    return JSON.parse(match[0]);
+export function parseTwitterArchive(raw: string): unknown {
+  const match = raw.match(/\[[\s\S]*\]/);
+  if (!match) {
+    throw new Error('Could not extract tweet array from Twitter archive file');
   }
-
-  return JSON.parse(raw);
+  return JSON.parse(match[0]);
 }
 
 export { convertTwitter } from './twitter.js';
diff --git a/packages/opal/src/index.ts b/packages/opal/src/index.ts
index 6d89587..02697ee 100644
--- a/packages/opal/src/index.ts
+++ b/packages/opal/src/index.ts
@@ -6,7 +6,7 @@
  */
 
 // Conversion
-export { convert } from './convert.js';
+export { convertData, parseTwitterArchive } from './convert.js';
 export { convertTwitter } from './twitter.js';
 export { convertMastodon } from './mastodon.js';
 export { convertThreads } from './threads.js';