diff --git a/src/commands.ts b/src/commands.ts
index c39bf2a..78d906d 100644
--- a/src/commands.ts
+++ b/src/commands.ts
@@ -1,5 +1,7 @@
 import { Plugin } from "obsidian";
 import { transformText, cleanText, bulletToEmdash, bulletToArrow, numberedListSlash, numberedListParens, markdownToLinkedIn, FormatStyle } from "./formatter";
+import { splitIntoThreads } from "./thread-splitter";
+import { ThreadModal } from "./thread-modal";
 
 function addFormatCommand(plugin: Plugin, style: FormatStyle, name: string) {
     plugin.addCommand({
@@ -78,4 +80,15 @@ export function registerCommands(plugin: Plugin): void {
             }
         },
     });
+    plugin.addCommand({
+        id: "unicode-formatter:split-thread",
+        name: "Split into X thread",
+        editorCallback: (editor) => {
+            const selection = editor.getSelection();
+            if (selection) {
+                const tweets = splitIntoThreads(selection);
+                new ThreadModal(plugin.app, tweets).open();
+            }
+        },
+    });
 }
diff --git a/src/formatter.ts b/src/formatter.ts
index 749b268..7f0ed35 100644
--- a/src/formatter.ts
+++ b/src/formatter.ts
@@ -75,53 +75,4 @@ export function numberedListParens(text: string): string {
     }).join("\n");
 }
 
-export function applyInlineMarkdown(text: string): string {
-    return text.replace(/\*\*(.+?)\*\*|_(.+?)_/g, (_match, bold: string | undefined, italic: string | undefined) => {
-        if (bold !== undefined) return transformText(bold, "bold");
-        return transformText(italic!, "italic");
-    });
-}
-
-export function markdownToLinkedIn(text: string): string {
-    const lines = text.split("\n");
-    const output: string[] = [];
-    let pendingBlanks = 0;
-    let skipNextBlanks = false;
-    let inListContext = false;
-
-    for (const line of lines) {
-        if (line.trim() === "") {
-            if (!skipNextBlanks) pendingBlanks++;
-            continue;
-        }
-
-        skipNextBlanks = false;
-
-        if (line.startsWith("## ")) {
-            for (let i = 0; i < pendingBlanks; i++) output.push("");
-            pendingBlanks = 0;
-            inListContext = false;
-            const headingText = line.slice(3);
-            output.push(transformText(applyInlineMarkdown(headingText), "bold") + "  ");
-            skipNextBlanks = true;
-            continue;
-        }
-
-        if (line.startsWith("- ") || line.startsWith("* ")) {
-            if (!inListContext) {
-                for (let i = 0; i < pendingBlanks; i++) output.push("");
-            }
-            pendingBlanks = 0;
-            output.push("— " + applyInlineMarkdown(line.slice(2)) + "  ");
-            inListContext = true;
-            continue;
-        }
-
-        for (let i = 0; i < pendingBlanks; i++) output.push("");
-        pendingBlanks = 0;
-        inListContext = false;
-        output.push(applyInlineMarkdown(line));
-    }
-
-    return output.join("\n").replace(/[ \u00A0]\./g, ".").trimEnd();
-}
+export { markdownToLinkedIn } from "./linkedin";
diff --git a/src/linkedin.ts b/src/linkedin.ts
new file mode 100644
index 0000000..5c00054
--- /dev/null
+++ b/src/linkedin.ts
@@ -0,0 +1,115 @@
+import { transformText } from "./formatter";
+
+function stripUnsupportedMarkdown(text: string): string {
+    return text
+        .replace(/!\[[^\]]*\]\([^)]+\)/g, "")
+        .replace(/\[([^\]]+)\]\(([^)]+)\)/g, "$1 ($2)")
+        .replace(/~~(.+?)~~/g, "$1")
+        .replace(/`(.+?)`/g, "$1");
+}
+
+function applyInlineMarkdown(text: string): string {
+    return text.replace(
+        /\*\*\*(.+?)\*\*\*|\*\*(.+?)\*\*|_(.+?)_/g,
+        (_match: string, boldItalic: string | undefined, bold: string | undefined, italic: string | undefined) => {
+            if (boldItalic !== undefined) return transformText(boldItalic, "bold-italic");
+            if (bold !== undefined) return transformText(bold, "bold");
+            return transformText(italic!, "italic");
+        }
+    );
+}
+
+export function markdownToLinkedIn(text: string): string {
+    const processed = stripUnsupportedMarkdown(text);
+    const lines = processed.split("\n");
+    const output: string[] = [];
+    let pendingBlanks = 0;
+    let skipNextBlanks = false;
+    let inListContext = false;
+
+    for (const line of lines) {
+        if (line.trim() === "") {
+            if (!skipNextBlanks) pendingBlanks++;
+            continue;
+        }
+
+        skipNextBlanks = false;
+
+        if (line.startsWith("# ")) {
+            for (let i = 0; i < pendingBlanks; i++) output.push("");
+            pendingBlanks = 0;
+            inListContext = false;
+            const headingText = line.slice(2).toUpperCase();
+            output.push(transformText(applyInlineMarkdown(headingText), "bold") + "  ");
+            skipNextBlanks = true;
+            continue;
+        }
+
+        if (line.startsWith("## ")) {
+            for (let i = 0; i < pendingBlanks; i++) output.push("");
+            pendingBlanks = 0;
+            inListContext = false;
+            const headingText = line.slice(3);
+            output.push(transformText(applyInlineMarkdown(headingText), "bold") + "  ");
+            skipNextBlanks = true;
+            continue;
+        }
+
+        const hMatch = line.match(/^#{3,6}\s/);
+        if (hMatch) {
+            for (let i = 0; i < pendingBlanks; i++) output.push("");
+            pendingBlanks = 0;
+            inListContext = false;
+            const headingText = line.slice(hMatch[0].length);
+            output.push(transformText(applyInlineMarkdown(headingText), "bold") + "  ");
+            skipNextBlanks = true;
+            continue;
+        }
+
+        if (line.startsWith("> ")) {
+            for (let i = 0; i < pendingBlanks; i++) output.push("");
+            pendingBlanks = 0;
+            inListContext = false;
+            output.push(transformText(applyInlineMarkdown(line.slice(2)), "italic"));
+            continue;
+        }
+
+        if (line.startsWith("- ") || line.startsWith("* ")) {
+            if (!inListContext) {
+                for (let i = 0; i < pendingBlanks; i++) output.push("");
+            }
+            pendingBlanks = 0;
+            output.push("— " + applyInlineMarkdown(line.slice(2)) + "  ");
+            inListContext = true;
+            continue;
+        }
+
+        const orderedMatch = line.match(/^(\d+)[.)]\s+(.+)/);
+        if (orderedMatch) {
+            if (!inListContext) {
+                for (let i = 0; i < pendingBlanks; i++) output.push("");
+            }
+            pendingBlanks = 0;
+            const num = orderedMatch[1]!;
+            const content = orderedMatch[2]!;
+            output.push(`${num}/ ${applyInlineMarkdown(content)}  `);
+            inListContext = true;
+            continue;
+        }
+
+        if (/^-{3,}$/.test(line.trim()) || /^\*{3,}$/.test(line.trim())) {
+            for (let i = 0; i < pendingBlanks; i++) output.push("");
+            pendingBlanks = 0;
+            inListContext = false;
+            output.push("");
+            continue;
+        }
+
+        for (let i = 0; i < pendingBlanks; i++) output.push("");
+        pendingBlanks = 0;
+        inListContext = false;
+        output.push(applyInlineMarkdown(line));
+    }
+
+    return output.join("\n").replace(/[ \u00A0]\./g, ".").trimEnd();
+}
diff --git a/src/thread-modal.ts b/src/thread-modal.ts
new file mode 100644
index 0000000..2aeb9ab
--- /dev/null
+++ b/src/thread-modal.ts
@@ -0,0 +1,72 @@
+import { App, Modal } from "obsidian";
+
+export class ThreadModal extends Modal {
+    private tweets: string[];
+
+    constructor(app: App, tweets: string[]) {
+        super(app);
+        this.tweets = tweets;
+    }
+
+    onOpen(): void {
+        const { contentEl } = this;
+        contentEl.empty();
+        contentEl.addClass("unicode-thread-modal");
+
+        const headingText = this.tweets.length === 1
+            ? "X post"
+            : `X thread (${this.tweets.length} posts)`;
+        contentEl.createEl("h3", { text: headingText });
+
+        const list = contentEl.createDiv({ cls: "thread-tweet-list" });
+
+        for (let i = 0; i < this.tweets.length; i++) {
+            const tweet = this.tweets[i]!;
+            const item = list.createDiv({ cls: "thread-tweet-item" });
+
+            const header = item.createDiv({ cls: "thread-tweet-header" });
+            if (this.tweets.length > 1) {
+                header.createSpan({
+                    text: `Post ${i + 1}/${this.tweets.length}`,
+                    cls: "thread-tweet-label",
+                });
+            }
+
+            item.createEl("textarea", {
+                text: tweet,
+                attr: { readonly: "true" },
+                cls: "thread-tweet-textarea",
+            });
+
+            const copyBtn = item.createEl("button", {
+                text: "Copy",
+                cls: "thread-copy-button",
+            });
+            copyBtn.addEventListener("click", () => {
+                navigator.clipboard.writeText(tweet).then(() => {
+                    copyBtn.setText("Copied");
+                    setTimeout(() => copyBtn.setText("Copy"), 2000);
+                }).catch(() => {});
+            });
+        }
+
+        if (this.tweets.length > 1) {
+            const copyAllBtn = contentEl.createEl("button", {
+                text: "Copy all",
+                cls: "thread-copy-all-button",
+            });
+            copyAllBtn.addEventListener("click", () => {
+                const all = this.tweets.join("\n\n");
+                navigator.clipboard.writeText(all).then(() => {
+                    copyAllBtn.setText("Copied");
+                    setTimeout(() => copyAllBtn.setText("Copy all"), 2000);
+                }).catch(() => {});
+            });
+        }
+    }
+
+    onClose(): void {
+        const { contentEl } = this;
+        contentEl.empty();
+    }
+}
diff --git a/src/thread-splitter.ts b/src/thread-splitter.ts
new file mode 100644
index 0000000..43e1c76
--- /dev/null
+++ b/src/thread-splitter.ts
@@ -0,0 +1,174 @@
+export interface ThreadOptions {
+    maxChars: number;
+    addNumbering: boolean;
+}
+
+const DEFAULT_OPTIONS: ThreadOptions = {
+    maxChars: 280,
+    addNumbering: true,
+};
+
+const NUMBERING_RESERVE = 8;
+
+function countChars(text: string): number {
+    let count = 0;
+    let lastIndex = 0;
+    const urlRe = /https?:\/\/\S+/g;
+    let match: RegExpExecArray | null;
+
+    while ((match = urlRe.exec(text)) !== null) {
+        count += match.index - lastIndex;
+        count += 23;
+        lastIndex = urlRe.lastIndex;
+    }
+    count += text.length - lastIndex;
+    return count;
+}
+
+function textFits(text: string, max: number): boolean {
+    return countChars(text) <= max;
+}
+
+function splitByWords(text: string, max: number): string[] {
+    const words = text.split(/\s+/);
+    const chunks: string[] = [];
+    let current = "";
+
+    for (const word of words) {
+        if (!current) {
+            current = word;
+            continue;
+        }
+        const candidate = current + " " + word;
+        if (countChars(candidate) <= max - 3) {
+            current = candidate;
+        } else {
+            chunks.push(current + "...");
+            current = word;
+        }
+    }
+
+    if (current) chunks.push(current);
+    return chunks;
+}
+
+function splitBySentences(text: string, max: number): string[] {
+    const sentences = text.match(/[^.!?\s][^.!?]*(?:[.!?]+|$)/g) || [text];
+    const chunks: string[] = [];
+    let current = "";
+
+    for (const sentence of sentences) {
+        if (!current) {
+            if (textFits(sentence, max)) {
+                current = sentence;
+            } else {
+                chunks.push(...splitByWords(sentence, max));
+            }
+        } else {
+            const candidate = current + sentence;
+            if (textFits(candidate, max)) {
+                current = candidate;
+            } else {
+                chunks.push(current);
+                if (textFits(sentence, max)) {
+                    current = sentence;
+                } else {
+                    chunks.push(...splitByWords(sentence, max));
+                    current = "";
+                }
+            }
+        }
+    }
+
+    if (current) chunks.push(current);
+    return chunks;
+}
+
+function splitBlock(text: string, max: number): string[] {
+    const lines = text.split("\n").filter(l => l.trim());
+    const chunks: string[] = [];
+    let current = "";
+
+    for (const line of lines) {
+        const trimmed = line.trim();
+        if (!current) {
+            if (textFits(trimmed, max)) {
+                current = trimmed;
+            } else {
+                chunks.push(...splitBySentences(trimmed, max));
+            }
+        } else {
+            const candidate = current + "\n" + trimmed;
+            if (textFits(candidate, max)) {
+                current = candidate;
+            } else {
+                chunks.push(current);
+                if (textFits(trimmed, max)) {
+                    current = trimmed;
+                } else {
+                    chunks.push(...splitBySentences(trimmed, max));
+                    current = "";
+                }
+            }
+        }
+    }
+
+    if (current) chunks.push(current);
+    return chunks.length > 0 ? chunks : [text];
+}
+
+export function splitIntoThreads(text: string, options?: Partial<ThreadOptions>): string[] {
+    const opts: ThreadOptions = Object.assign({}, DEFAULT_OPTIONS, options);
+    const effectiveMax = opts.addNumbering ? opts.maxChars - NUMBERING_RESERVE : opts.maxChars;
+    const paragraphs = text.split(/\n{2,}/).filter(p => p.trim());
+
+    if (paragraphs.length === 0) return [];
+
+    const rawTweets: string[] = [];
+    let current = "";
+
+    for (const para of paragraphs) {
+        const trimmed = para.trim();
+
+        if (!current) {
+            if (textFits(trimmed, effectiveMax)) {
+                current = trimmed;
+            } else {
+                const chunks = splitBlock(trimmed, effectiveMax);
+                if (chunks.length > 1) {
+                    rawTweets.push(...chunks.slice(0, -1));
+                    current = chunks[chunks.length - 1]!;
+                } else {
+                    current = chunks[0]!;
+                }
+            }
+        } else {
+            const candidate = current + "\n\n" + trimmed;
+            if (textFits(candidate, effectiveMax)) {
+                current = candidate;
+            } else {
+                rawTweets.push(current);
+                if (textFits(trimmed, effectiveMax)) {
+                    current = trimmed;
+                } else {
+                    const chunks = splitBlock(trimmed, effectiveMax);
+                    if (chunks.length > 1) {
+                        rawTweets.push(...chunks.slice(0, -1));
+                        current = chunks[chunks.length - 1]!;
+                    } else {
+                        current = chunks[0]!;
+                    }
+                }
+            }
+        }
+    }
+
+    if (current) rawTweets.push(current);
+
+    if (opts.addNumbering && rawTweets.length > 1) {
+        const total = rawTweets.length;
+        return rawTweets.map((tweet, i) => `${i + 1}/${total} ${tweet}`);
+    }
+
+    return rawTweets;
+}
diff --git a/styles.css b/styles.css
index 71cc60f..bd27393 100644
--- a/styles.css
+++ b/styles.css
@@ -1,8 +1,45 @@
-/*
+.unicode-thread-modal .thread-tweet-list {
+    display: flex;
+    flex-direction: column;
+    gap: 16px;
+    margin-bottom: 16px;
+}
 
-This CSS file will be included with your plugin, and
-available in the app when your plugin is enabled.
+.unicode-thread-modal .thread-tweet-item {
+    display: flex;
+    flex-direction: column;
+    gap: 4px;
+}
 
-If your plugin does not need CSS, delete this file.
+.unicode-thread-modal .thread-tweet-header {
+    display: flex;
+    align-items: center;
+    gap: 8px;
+}
 
-*/
+.unicode-thread-modal .thread-tweet-label {
+    font-weight: 600;
+    font-size: 0.85em;
+    color: var(--text-muted);
+}
+
+.unicode-thread-modal .thread-tweet-textarea {
+    width: 100%;
+    min-height: 60px;
+    resize: vertical;
+    font-family: var(--font-text);
+    font-size: var(--font-text-size);
+    padding: 8px;
+    border: 1px solid var(--background-modifier-border);
+    border-radius: 4px;
+    background: var(--background-secondary);
+    color: var(--text-normal);
+}
+
+.unicode-thread-modal .thread-copy-button {
+    align-self: flex-end;
+}
+
+.unicode-thread-modal .thread-copy-all-button {
+    width: 100%;
+}