Free webp to jpg
FastBid

FastBid Sheet

image/vnd.fastbidsheet Released Late 1990s · by FastBid, Inc. (Scott Becker)

The image/vnd.fastbidsheet MIME type represents a proprietary image format used by FastBid, a legacy estimating and blueprint-viewing software for the construction industry. Today, this MIME type is most infamous in the developer community for causing widespread MIME-sniffing conflicts: standard web servers, MIME databases, and file parsers often misidentify modern Google FlatBuffers schema files (which also use the .fbs extension) as FastBid images, leading to unexpected errors in modern development pipelines and AI SDKs.

Legacy & Proprietary Production Ready

Technical Specifications

MIME Type
image/vnd.fastbidsheet
Extensions
.fbs
Container
Proprietary FastBid Container
Compression
Proprietary
Algorithms
Unknown
Color Depth
Unknown
Metadata
None
Capabilities
Transparency
Animation
Progressive Loading
Alpha Channel
HDR Support

Magic Bytes & HTTP Headers

File Signature (Magic Bytes)
Unknown (Proprietary)
ASCII: Unknown
HTTP Headers
Content-Type: image/vnd.fastbidsheet
HTML Accept Attribute
accept="None"

Browser Support Matrix

Browser Status Min Version
Chrome Chrome
Not Supported
Firefox Firefox
Not Supported
Safari Safari
Not Supported
Edge Edge
Not Supported
Internet Explorer Internet Explorer
Not Supported Legacy

Advantages & Limitations

Advantages
  • Historically allowed the FastBid application to securely associate and load proprietary construction plans within its ecosystem
Limitations
  • Completely obsolete and unsupported in modern software environments
  • The official IANA registration of the .fbs extension causes widespread false positives, breaking modern parsers, text editors, and AI SDKs attempting to read FlatBuffers schemas

Developer Code Snippets

import mimetypes
# Override the default OS/IANA registry mapping to fix FlatBuffers conflicts
mimetypes.add_type('text/plain', '.fbs')
print(mimetypes.guess_type('schema.fbs')) # Now correctly outputs ('text/plain', None) instead of 'image/vnd.fastbidsheet'
const mime = require('mime');
// Many JS MIME libraries map .fbs to image/vnd.fastbidsheet by default based on the IANA DB
console.log(mime.getType('schema.fbs')); // Likely outputs 'image/vnd.fastbidsheet'
// Workaround: explicitly define standard text overrides in your file parsers
import "mime"
// Override the default OS-level MIME database mapping for Go applications using FlatBuffers
func init() {
    mime.AddExtensionType(".fbs", "text/plain; charset=utf-8")
}
// In web server configurations (like Apache/Nginx), you must explicitly map .fbs to text/plain
// Otherwise, PHP upload scripts will receive 'image/vnd.fastbidsheet' as the detected Content-Type for FlatBuffer files.

File Detection Steps

How to programmatically detect a image/vnd.fastbidsheet file by reading its raw bytes:

  1. 1 Due to its obscurity, file detection almost entirely relies on matching the .fbs extension to the IANA registry.
  2. 2 Developers working with FlatBuffers must actively bypass or override strict MIME detection for .fbs to prevent text files from being improperly base64-encoded or treated as binary FastBid images.

Software Support

F
FastBid (Legacy)

Share & Embed

Markdown Badge
FastBid Format Badge
[![FastBid Format](https://freewebptojpg.com/mime/image/fastbid/badge.svg)](https://freewebptojpg.com/mime/image/fastbid)
Interactive iframe Widget
<iframe src="https://freewebptojpg.com/mime/image/fastbid/embed" width="100%" height="280" style="border:1px solid #cbd5e1;border-radius:8px;" title="FastBid Specs"></iframe>

JSON API

All data on this page is available as a free, open JSON API. Use it in your project, documentation, or tooling.

GET https://freewebptojpg.com/mime/image/fastbid.json Open JSON
Free to use
No auth required
CORS enabled
Use from any domain
Cached 24h
Cache-Control headers set

Frequently Asked Questions

Why is my FlatBuffers .fbs file being detected as an image?

The .fbs file extension is officially registered with IANA as image/vnd.fastbidsheet, a proprietary format for legacy FastBid construction software. Because standard MIME sniffers and operating system registries prioritize the official IANA database, they mistakenly identify your FlatBuffers schema text files as FastBid binary images.

What is a FastBid Sheet?

A FastBid Sheet is an obsolete proprietary format used by the FastBid construction estimating software to store digital blueprints, construction plans, and architectural layouts.

How do I fix the .fbs MIME type conflict in my application?

If your application processes FlatBuffers schemas, you must explicitly override your MIME detection library or web server configuration (like Nginx, Apache, or Python's mimetypes module) to map the .fbs extension to text/plain instead of relying on the default image/vnd.fastbidsheet fallback.

Share this format