If you use Claude on a daily basis, have you ever experienced any of these?
- Manually copy-pasting the same prompts over and over
- Wanting to send data from your web app to Claude, but API usage is costly
- Finding it tedious to share "try asking with this prompt" with team members
Send to Claude solves all of these with a single Chrome extension.
What Can It Do?
In a nutshell, it's a Chrome extension that lets you programmatically control Claude prompts through URL parameters and a JavaScript API.
What does this mean? It transforms Claude prompt input from "something you type by hand" to "something you can automate".
And because it operates Claude Chat directly in the browser without using the Claude API, there are zero API usage fees. Whether you're on a free Claude account or Claude Pro, your everyday Claude Chat becomes the target of automation.
The Best Feature: Pass Prompts via URL Parameters
The usage couldn't be simpler. Just add ?prompt= to the Claude URL.
https://claude.ai/new?prompt=Tell me about today's weather
Simply open this URL in your browser, and the prompt is auto-filled and auto-submitted. That's all there is to it.
What This Makes Possible
1. Bookmarks Become Prompts
Save your frequently used questions or prompts as bookmarks, and you can ask Claude with a single click.
📌 Daily News Summary
https://claude.ai/new?prompt=Summarize today's top news in 3 bullet points
📌 English Email Proofreading
https://claude.ai/new?prompt=Please proofread the following English email:&autosubmit=false
Adding autosubmit=false will only fill in the prompt without submitting, so you can add more text before sending.
2. Share Prompts with Your Team
Just paste a URL in Slack or Notion, and everyone on the team can ask Claude using the same prompt.
"Try asking about the root cause of this outage with this prompt:"
https://claude.ai/new?prompt=Analyze the following error logs and provide the root cause and recommended actions:
No more being asked "What prompt should I use?"
3. Embed in Links from External Tools
You can add an "Analyze with Claude" button to dashboards and internal tools. Just dynamically generate URLs, and any tool can integrate with Claude.
Another Powerful Feature: JavaScript API for External Integration
URL parameters alone are powerful enough, but Send to Claude goes further by providing a JavaScript API.
This lets you send prompts to Claude directly from your own web pages and web apps.
const extensionId = "your-extension-id";
chrome.runtime.sendMessage(
extensionId,
{
type: "autofill",
prompt: "Please analyze this data:\n" + yourData,
autoSubmit: true
},
(response) => {
if (response?.success) {
console.log("Successfully sent to Claude!");
}
}
);
Differences from URL Parameters
| URL Parameters | JavaScript API | |
|---|---|---|
| Ease of Use | â—Ž Just paste a URL | â—‹ Requires code |
| Text Volume | â–³ URL length limits | â—Ž Thousands of lines OK |
| Dynamic Data | â–³ Encoding required | â—Ž Pass variables directly |
| Use Cases | Bookmarks, link sharing | Web app integration, data analysis |
With the JavaScript API, you can send thousands of lines of logs or code directly to Claude without worrying about URL length limits.
And let me emphasize again: all of this is available completely free of charge. Normally, calling Claude from an application requires a Claude API contract with pay-per-token billing. But Send to Claude is simply a browser extension that operates Claude Chat. No API key needed, no charges at all. Whether for personal projects or team experimentation, you can try Claude integration without worrying about costs.
async/await Support
For modern JavaScript, you can easily write a Promise-based version.
function sendToClaude({ prompt, autoSubmit = true }) {
return new Promise((resolve, reject) => {
chrome.runtime.sendMessage(
extensionId,
{ type: "autofill", prompt, autoSubmit },
(response) => {
if (chrome.runtime.lastError) {
reject(new Error(chrome.runtime.lastError.message));
} else if (response?.success) {
resolve(response);
} else {
reject(new Error("Failed to send"));
}
}
);
});
}
// Usage
await sendToClaude({
prompt: "Please review the following code:\n" + codeBlock,
autoSubmit: true
});
Even More Handy Features
Instant Send via Right-Click Menu
Select text on a web page, right-click → "Send to Claude." That's it — a new Claude tab opens with the selected text filled in as the prompt.
Send interesting articles or error messages to Claude without any copy-and-paste.
Custom Prompts
Register frequently used prompt templates like "Translate to English," "Summarize," or "Explain this code" in the right-click menu.
Selected text + custom prompt are automatically combined, so just select text and right-click to complete translation or summarization in a single action.
You can also configure auto-submit on/off for each custom prompt individually — a nice touch.
8 Languages Supported
Supports Japanese, English, German, Spanish, French, Korean, Portuguese, and Chinese. The UI automatically switches based on your browser's language settings.
Usage Ideas
| Scenario | Method |
|---|---|
| Daily news summary | Bookmark a URL |
| Code review requests | Auto-send via JavaScript API |
| Article translation | Select text → Right-click → Custom prompt |
| Error log analysis | Send large text via JavaScript API |
| Sharing prompts with team | Paste URL in Slack/Notion |
| Internal tool integration | Add "Analyze with Claude" button via API |
Conclusion
The essence of Send to Claude is making Claude programmable.
- URL parameters for easy automation through bookmarks and link sharing
- JavaScript API for full-fledged external integration from web apps
No Claude API contract, no API keys, no server-side implementation needed. Achieving all of this in the browser alone at zero cost is groundbreaking.
If you want to weave Claude more deeply into your daily workflow, give it a try.
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