Use the FindUtils HTML Entity Finder, HTTP Status Code Lookup, and MIME Type Finder for focused reference searches. Each tool searches a bundled dataset. Confirm standards-sensitive values against the relevant specification or registry. A search match is a reference aid, not a complete validation of your application.
1. HTML Entity Finder
The HTML Entity Finder puts a selection of HTML entities into a single, searchable interface. Type a keyword like "arrow," "copy," or "dash" and fuzzy search instantly filters the results. Each entity card shows the rendered character, its human-readable name, and three copyable formats: the named entity (→), the decimal code (→), and the hex code (→). One click copies any format to your clipboard.
Entities are organized into categories — Currency Symbols, Math Symbols, Arrows, Latin Characters, Greek Letters, and more — so you can also browse by type when you are not sure exactly what you are looking for. Need a Greek letter for a math formula in your documentation? Filter to Greek Letters and scan visually instead of guessing search terms.
Quick example: Type "non-breaking" to instantly find along with its decimal and hex equivalents. Check the copied value before use.
2. HTTP Status Code Lookup
The HTTP Status Code Lookup contains a selection of HTTP status codes with color-coded categories (1xx Informational, 2xx Success, 3xx Redirection, 4xx Client Error, 5xx Server Error) so you can visually distinguish response classes at a glance. Green for success, blue for redirects, amber for client errors, red for server errors.
Expand an HTTP entry for its explanation and example. A suggested solution is a starting point; the same status can have several application-specific causes.
The fuzzy search works on code numbers, names, descriptions, and keywords. Type "cache" and you will see 304 Not Modified alongside other cache-related codes. Type "auth" and both 401 Unauthorized and 403 Forbidden appear, making it easy to compare them side by side.
Quick example: Search "rate" to find 429 Too Many Requests, then expand it to see the recommended solution (implement exponential backoff and check Retry-After headers) without leaving the page.
3. MIME Type Finder
The MIME Type Finder indexes a selection of MIME types across eight categories: Application, Audio, Font, Image, Text, Video, Multipart, and Message. Each entry shows the full MIME type string, a human-readable description, the associated file extensions, and a color-coded category badge. Both the MIME type and extension list are individually copyable with one click.
The search is bidirectional. You can type a file extension like .webp to find image/webp, or type a partial MIME string like application/json to find the exact entry along with its extensions. This is particularly helpful when you are working backwards from a Content-Type header in a network inspector and need to know what file types it covers.
Quick example: Type "pdf" and immediately find application/pdf with its .pdf extension. Type "zip" and see both application/zip and application/x-zip-compressed — a distinction that matters when your server needs to handle both.
Match each reference to the task
| Task | Reference | Check after lookup |
|---|---|---|
| Insert a right arrow | HTML Entity Finder | Use the correct encoding for HTML, not another output context |
| Diagnose HTTP 502 | HTTP Status Code Lookup | Inspect the gateway and upstream response records |
| Send a WOFF2 font | MIME Type Finder | Check the response's actual Content-Type |
| Compare HTTP 401 and 403 | HTTP Status Code Lookup | Match the application authentication and authorization state |
| Find currency symbols | HTML Entity Finder | Confirm the currency and locale, not only the symbol |
These are workflow examples, not measured time savings. The correct next step depends on the application and the protocol.
Use approximate search carefully
Fuzzy search matches partial names and similar text. It can help when you do not remember the exact spelling. It can also return a nearby result that is not the value you need.
The bundled data supports local lookups. This does not establish that the entire website has no network activity. Use ordinary non-secret reference terms.
Copying a value avoids retyping it, but it does not validate its use. For example, HTML entities are not a general escaping method for JavaScript, SQL, or URLs.
Use the WHATWG named character reference, IANA HTTP status registry, and IANA media type registry when standards coverage matters.
The cURL to Code Converter can help reproduce a request after a status lookup. Keep response headers and the server's error details available for diagnosis.
Get Started
Keep these references available for recurring lookups:
- HTML Entity Finder — HTML entities with fuzzy search and one-click copy
- HTTP Status Code Lookup — HTTP status codes with use cases and solutions
- MIME Type Finder — MIME types searchable by extension or MIME string
All three tools are free, require no account, and run entirely in your browser. FindUtils is building a growing library of developer reference tools — if there is a lookup you perform repeatedly that you think deserves the same treatment, check the full developer tools collection for more.
Frequently asked questions
Are these complete standards registries?
No. They are convenient bundled references. Consult the relevant official registry for complete or newly registered values.
Does a MIME type prove that a file is safe?
No. A filename and declared Content-Type can be wrong. Validate file content and apply the controls required for the upload workflow.
Does an HTTP status code identify the exact defect?
No. It describes a response condition. Inspect the request, response, and application context to find the cause.
Is every HTML entity valid in every programming language?
No. HTML character references belong to HTML parsing contexts. Use the escaping rules for the actual output language.
Does fuzzy search guarantee the intended match?
No. Check the name, code, and description before copying the result.
