"Best URL shortener" is a marketing question unless you are a developer. A developer needs specific things: a clean API, no arbitrary quotum, no signup wall, and — increasingly — a server an AI agent can call. Here is what "best for developers" actually means and who does it.
What developers actually need
- A real API. You want to shorten from code, not click a button in a browser.
- No signup wall. You want a link in one command, not a dashboard onboarding.
- Unlimited, not a quota. An automation should not hit a cap at 9am on a Tuesday.
- Permanent links. A link you put in a commit or a README should work next year.
- A stable slug format. So scripts and templates can rely on the output shape.
- The AI-agent story. By 2026, "developer tool" increasingly means "works from my MCP client."
The candidates
Bitly. Brand recognition, but a thin free tier (a handful of links a month) and an account requirement. Weak as a developer tool.
TinyURL / is.gd. Quick anonymous links, no signup, unlimited — but no meaningful API or analytics. Fine for a one-off, not a tool you build on.
Dub. The open-source developer favorite. Great if you want to self-host and own your stack. The trade-off is you stand up and maintain your own server, and the hosted tier is metered.
Short.io / Rebrandly. Solid branded-link tools, but paid tiers and API keys to manage.
KooLink. Free, unlimited, no signup to shorten, a REST API, honest click tracking, and a hosted MCP server. The agent story is the differentiator — no other widely-used shortener exposes an MCP server.
Why the MCP server is the developer story
The Model Context Protocol is how AI agents consume tools. If you work in Claude Code, Cursor, Windsurf, VS Code with Continue, or any MCP client, you point it at a server and the agent gets a shorten_url tool.
https://mcp.kool.ink
Then you ask the agent to shorten a URL and it does — no browser, no copy-paste.
That turns kool.ink from "a website" into "a tool your agent has loaded." No competitor does this.
The developer comparison
| Feature | Bitly | is.gd | Dub | KooLink |
|---|---|---|---|---|
| No signup to shorten | No | Yes | No | Yes |
| Unlimited links (free) | No | Yes | No | Yes |
| REST API | Paid | No | Yes | Yes |
| Click analytics (free) | No | No | Yes | Yes |
| Hosted MCP server | No | No | No | Yes |
That last row is the one nobody else fills.
Try it
- From code:
POST https://kool.ink/api/linkswith{ "url": "..." } - From your agent: point it at
https://mcp.kool.ink - From your terminal:
npx @koolink/koolink https://example.com/long/path
Free forever. Unlimited. No signup.