Convert images to WebP in Claude
Add Fast WebP Converter to Claude as a connector and ask for WebP in plain words: “convert this hero image”, “shrink these product photos”, “how heavy are the images on my homepage?”. Claude calls the converter, the result shows as a card in the conversation, and you get a download link with the size before and after. It works on claude.ai, in Claude Desktop and the phone apps, and in Claude Code, where a plugin also converts the images of your project.
Connected in a minute
Three steps, the first two once.
Add the connector
Press Add to Claude on this page: Claude opens Customize, Connectors, Add custom connector with the name and the address (https://www.fastwebpconverter.com/api/mcp) already filled in. Press Add. No client ID or secret.
Connect your account
Press Connect. A Fast WebP Converter window opens: sign in with a code sent to your e-mail, or with Google (a free account is created if you have none), then allow Claude.
Ask for WebP
In a chat, make sure the connector is on in the + menu, then paste an image URL or a page address and say what you want. The result card shows the sizes and the download link.
What you can ask
Requests that work as they are. Claude picks the right tool and the options; you can always name a quality or a width.
- “Convert https://example.com/images/hero.png to WebP at quality 80, 1600 px wide at most.”
- “Audit https://example.com and tell me how much I would save by serving its images as WebP.”
- “Convert these product photos to WebP and give me one ZIP: (paste the image URLs)”
- “Turn this animated GIF into an animated WebP: https://example.com/demo.gif”
- “Convert our logo to lossless WebP: https://example.com/logo.png”
- “How many WebP conversions do I have left this month?”
Claude is good at the judgement calls around the conversion: it reads the audit, tells you which images matter for page speed, suggests a width per image and explains the trade-offs. The connector does the encoding.
What Claude can do with it
- Convert one image (
convert_image): Converts one image to WebP, from a public URL or from image data (base64), with quality, maximum width and lossless options. Returns a download link, the original and WebP sizes, the dimensions and the percentage saved. - Convert a batch (
convert_images): Converts several images in one call (up to 5 on Free, 50 on Pro) and returns one ZIP download link with the sizes of each file. - Audit a web page (
audit_page): Reads a public web page, lists its images with their format and weight, and estimates how much converting them to WebP would save. A starting point for a page-speed plan. The same audit is free on the website at https://www.fastwebpconverter.com/audit. - Your account (
get_account): Your plan, the conversions used and left this month and when the allowance resets. - Plans and prices (
get_pricing): The current plans and prices, so the assistant quotes the real figures instead of guessing.
Formats read on the server: JPG, PNG, GIF, WebP, AVIF, TIFF and SVG. Animated GIFs come out as animated WebP. HEIC photos and BMP files are not read on the server: the browser converter handles them (HEIC in Safari).
audit_page uses no conversion, and the same audit is free on the website: paste a URL in the image audit and see each image's real WebP saving, no account needed.
Claude Code: optimise the images of your project
Connectors belong to your Claude account, so the one you add on claude.ai also shows in Claude Desktop and the phone apps. In Claude Code, add the same server from the terminal:
Claude Code — bash
Claude Code, with an API key instead of OAuth — bash
The Fast WebP plugin for Claude Code
The plugin bundles the connector with two skills and a /webp command. optimize-images-to-webp inventories the images in your repository, converts them (remote images through the connector, local files through the API with your FASTWEBP_API_KEY), keeps the originals, updates the references in HTML, CSS, JSX and Markdown with <picture> fallbacks where they make sense, and reports the bytes saved. audit-site-images runs audit_page on your live pages and turns the result into a plan. Source: gabrielstik/fastwebp-plugin(opens in new tab).
Install the plugin
In Claude Code
Then run /webp public/images (or any folder) in a session. For local files, create an API key on your account page and export it as FASTWEBP_API_KEY before starting Claude Code; the key works for the connector too.
Free and paid plans
Adding the connector is free on every Claude plan. A free Fast WebP Converter account is the way to try it: 50 conversions a month on the server, shared by Claude, ChatGPT, every MCP client and the API. Pro is full access, paid monthly, yearly or once for life ($4.99/month, $29/year or $59 once), with 10,000 server conversions a month (fair use). The monthly allowance resets on the 1st (UTC).
What each plan allows on the server (API, Claude, ChatGPT, MCP clients)
| Plan | Price | Server conversions | Images per batch call | Image by URL up to | API requests a minute | Download links kept |
|---|---|---|---|---|---|---|
| Free | Free | 50 a month | 5 | 10 MB | 10 | 24 hours |
| Pro | $4.99/month, $29/year or $59 once | 10,000 a month | 50 | 25 MB | 120 | 3 days |
Cancel anytime from your account. 14-day money-back guarantee. Ask Claude “how many conversions do I have left?” at any time.
What Claude and Fast WebP Converter see
The assistant sends Fast WebP Converter only what a tool needs: the image URL or image data, the options (quality, maximum width, lossless) and, for an audit, the page address. It never sees the rest of the conversation. Originals are processed in memory and not kept; converted files stay behind an unguessable download link for 24 hours on Free (3 days on Pro), then they are deleted. Details in the privacy policy.
The browser converter on the home page is still the private option for files on your computer: it encodes on your device and uploads nothing.
Questions
Claude can explain WebP and write conversion code, but to convert your images it needs a tool. The Fast WebP Converter connector is one: Claude sends the image or its URL, the server encodes it with libwebp and returns a download link with the size before and after, as a card in the conversation.
Open Customize, Connectors in Claude, press +, Add custom connector, name it Fast WebP Converter and paste https://www.fastwebpconverter.com/api/mcp; the Add to Claude button on https://www.fastwebpconverter.com/integrations/claude opens that dialog already filled in. Press Connect, sign in with an e-mail code or Google and allow Claude. In Claude Code: claude mcp add --transport http fastwebp https://www.fastwebpconverter.com/api/mcp.
Adding it is free. A free Fast WebP Converter account is the way to try it: 50 conversions a month on the server, shared by Claude, ChatGPT, every MCP client and the API. Pro is full access, paid monthly, yearly or once for life ($4.99/month, $29/year or $59 once), with 10,000 server conversions a month (fair use). The monthly allowance resets on the 1st (UTC).
Custom connectors are available on every Claude plan; at the time of writing the free plan allows one custom connector. On Team and Enterprise, an owner adds the connector for the organisation and each member connects their own account.
Yes. Add the server with claude mcp add, or install the plugin (/plugin marketplace add gabrielstik/fastwebp-plugin, then /plugin install fastwebp@fastwebp). For files on disk, Claude Code calls the REST API with your API key; it keeps the originals and updates the references in your code.
JPG, PNG, GIF, WebP, AVIF, TIFF and SVG, to WebP. Animated GIFs come out as animated WebP. HEIC photos and BMP files are not read on the server: the browser converter handles them (HEIC in Safari). Images by URL can be up to 10 MB on Free and 25 MB on paid plans.
No. It reads the images you point it to and returns converted copies as download links. Nothing on your site changes until you upload the WebP files or deploy the updated code.
Related
Give Claude a WebP encoder
Add the connector, sign in, and ask for your first conversion. 50 conversions a month are free with an account.