Developer API

Integrate file conversion into your apps. Documentation is public — sign in to create API keys. All /api/v1 calls require a key.

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Quick start

All endpoints live under https://your-domain.com/api/v1. Send multipart/form-data for file uploads or application/json where noted. Call from your backend or serverless function — not from browser client code if you want to protect quota.

curl -X POST "https://your-domain.com/api/v1/tools/compress" \
  -H "X-API-Key: fc_live_YOUR_KEY" \
  -F "file=@photo.jpg" \
  -F "quality=80" \
  -o compressed.jpg

Authentication

Every /api/v1 request must include an API key. Sign in on this page to create a personal key, or use the server API_KEY from your deployment environment.

Header: Authorization: Bearer fc_live_…
Or: X-API-Key (personal key or env API_KEY)

The OpenAPI spec at /api/v1/openapi.json also requires authentication. Keys are for server-side use only.

Rate limits

Per API key

300/min

Exceeded limits return 429 with a Retry-After header (seconds).

Errors

Status	Meaning
400	Invalid request (missing file, unsupported format)
401	Invalid or revoked API key
413	File too large
429	Rate limit exceeded
500	Server processing error

{
  "error": "Rate limit exceeded",
  "code": "RATE_LIMIT_EXCEEDED"
}

File limits

Images: 200MB
Documents: 200MB
Archives (single): 500MB
ZIP bundle (total): 500MB
Remote import: 100MB

Images up to 200MB · Video/audio up to 2GB · Documents up to 200MB · Archives up to 500MB

Convert API

POST

/api/v1/convert/images

Convert or transform an image

Convert images between formats (JPG, PNG, WebP, AVIF, TIFF, GIF, HEIC). Optional resize, crop, rotate, and watermark. Max 200MB per file.

Parameters

Name	Type	Required	Description
file	file	Yes	Source image file
format	string	Yes	Target format (e.g. png, webp, jpg)
quality	number	No	Output quality 1–100 (default 90)
width	number	No	Resize width in pixels
height	number	No	Resize height in pixels
fit	string	No	Resize fit: cover, contain, fill, inside, outside
rotate	number	No	Rotation in degrees
watermark	file	No	Watermark image overlay

Content-Type: multipart/form-data · Response: binary

Returns the converted image with Content-Disposition attachment headers.

Example

curl -X POST "https://your-domain.com/api/v1/convert/images" \
  -F "file=@photo.jpg" \
  -F "format=webp" \
  -F "quality=85" \
  -o output.webp

POST

/api/v1/convert/documents

Convert documents

Convert between document formats (PDF, DOCX, TXT, RTF, XLSX, etc.). Max 200MB per file.

Parameters

Name	Type	Required	Description
file	file	Yes	Source document
format	string	Yes	Target format

Content-Type: multipart/form-data · Response: binary

Returns the converted document file.

Example

curl -X POST "https://your-domain.com/api/v1/convert/documents" \
  -F "file=@report.docx" \
  -F "format=pdf" \
  -o report.pdf

POST

/api/v1/convert/pdf

Images to PDF

Merge one or more images into a single PDF. Max 200MB per image.

Parameters

Name	Type	Required	Description
file	file	Yes	One or more image files (repeat field)
format	string	Yes	Must be "pdf"

Content-Type: multipart/form-data · Response: binary

Returns a PDF file.

Example

curl -X POST "https://your-domain.com/api/v1/convert/pdf" \
  -F "file=@page1.png" \
  -F "file=@page2.png" \
  -F "format=pdf" \
  -o combined.pdf

POST

/api/v1/convert/archive/create

Create a ZIP archive

Bundle multiple files into one ZIP. Total size up to 500MB.

Parameters

Name	Type	Required	Description
file	file	Yes	Files to include (repeat field)
filename	string	No	Output filename (default archive.zip)

Content-Type: multipart/form-data · Response: binary

Returns a ZIP archive.

Example

curl -X POST "https://your-domain.com/api/v1/convert/archive/create" \
  -F "file=@doc.pdf" \
  -F "file=@image.png" \
  -F "filename=bundle.zip" \
  -o bundle.zip

POST

/api/v1/convert/archive/extract

Extract ZIP contents

List and extract files from a ZIP archive. Max 500MB.

Parameters

Name	Type	Required	Description
file	file	Yes	ZIP archive file

Content-Type: multipart/form-data · Response: json

Returns JSON with archive metadata and entry list.

Example

curl -X POST "https://your-domain.com/api/v1/convert/archive/extract" \
  -F "file=@archive.zip"

Tools API

POST

/api/v1/tools/compress

Compress an image

Reduce image file size. Supports JPG, PNG, WebP, AVIF, TIFF. Max 200MB.

Parameters

Name	Type	Required	Description
file	file	Yes	Image to compress
quality	number	No	Quality 1–100 (default 70)

Content-Type: multipart/form-data · Response: binary

Returns compressed image. Headers X-Original-Size and X-Compressed-Size included.

Example

curl -X POST "https://your-domain.com/api/v1/tools/compress" \
  -F "file=@input.jpg" \
  -F "quality=70" \
  -o output.jpg

POST

/api/v1/tools/archive/create-zip

Create ZIP archive

Same as convert/archive/create. Total up to 500MB.

Parameters

Name	Type	Required	Description
file	file	Yes	Files to bundle (repeat field)
filename	string	No	Output filename

Content-Type: multipart/form-data · Response: binary

Returns a ZIP file.

Example

curl -X POST "https://your-domain.com/api/v1/tools/archive/create-zip" \
  -F "file=@a.pdf" \
  -F "file=@b.png" \
  -o my-archive.zip

POST

/api/v1/tools/archive/extract

Inspect or convert archives

Inspect ZIP contents or convert TAR/TGZ/TBZ2 to ZIP. Max 500MB.

Parameters

Name	Type	Required	Description
file	file	Yes	Archive file (ZIP, TAR, TGZ, TBZ2)

Content-Type: multipart/form-data · Response: json

ZIP returns JSON entry list; other formats may return a converted ZIP binary.

Example

curl -X POST "https://your-domain.com/api/v1/tools/archive/extract" \
  -F "file=@archive.zip"

POST

/api/v1/tools/rar-to-zip

Convert RAR to ZIP

Convert a RAR archive to ZIP format. Max 500MB.

Parameters

Name	Type	Required	Description
file	file	Yes	RAR archive file

Content-Type: multipart/form-data · Response: binary

Returns a ZIP file.

Example

curl -X POST "https://your-domain.com/api/v1/tools/rar-to-zip" \
  -F "file=@archive.rar" \
  -o archive.zip

Integrations API

POST

/api/v1/integrations/import

Import from cloud URL

Download a file from Google Drive or Dropbox and store it for processing. Max 100MB per file.

Parameters

Name	Type	Required	Description
url	string	Yes	Public Google Drive or Dropbox share URL

Content-Type: application/json · Response: json

Returns JSON with file metadata and storage reference.

Example

curl -X POST "https://your-domain.com/api/v1/integrations/import" \
  -H "Content-Type: application/json" \
  -d '{"url":"https://www.dropbox.com/s/..."}'

Roadmap

Video and audio conversion through the REST API is available for supported formats within upload limits. Very large files may need the in-browser web tools or homepage converter instead of a single API request.

10 endpoints available · OpenAPI spec at /api/v1/openapi.json (authenticated)

Developer API

Integrate file conversion into your apps. Documentation is public — sign in to create API keys. All /api/v1 calls require a key.

On this page

Checking session…

Quick start

curl -X POST "https://your-domain.com/api/v1/tools/compress" \
  -H "X-API-Key: fc_live_YOUR_KEY" \
  -F "file=@photo.jpg" \
  -F "quality=80" \
  -o compressed.jpg

Authentication

Every /api/v1 request must include an API key. Sign in on this page to create a personal key, or use the server API_KEY from your deployment environment.

Header: Authorization: Bearer fc_live_…
Or: X-API-Key (personal key or env API_KEY)

The OpenAPI spec at /api/v1/openapi.json also requires authentication. Keys are for server-side use only.

Rate limits

Per API key

300/min

Exceeded limits return 429 with a Retry-After header (seconds).

Errors

Status	Meaning
400	Invalid request (missing file, unsupported format)
401	Invalid or revoked API key
413	File too large
429	Rate limit exceeded
500	Server processing error

{
  "error": "Rate limit exceeded",
  "code": "RATE_LIMIT_EXCEEDED"
}

File limits

Images: 200MB
Documents: 200MB
Archives (single): 500MB
ZIP bundle (total): 500MB
Remote import: 100MB

Images up to 200MB · Video/audio up to 2GB · Documents up to 200MB · Archives up to 500MB

Convert API

POST

/api/v1/convert/images

Convert or transform an image

Convert images between formats (JPG, PNG, WebP, AVIF, TIFF, GIF, HEIC). Optional resize, crop, rotate, and watermark. Max 200MB per file.

Parameters

Name	Type	Required	Description
file	file	Yes	Source image file
format	string	Yes	Target format (e.g. png, webp, jpg)
quality	number	No	Output quality 1–100 (default 90)
width	number	No	Resize width in pixels
height	number	No	Resize height in pixels
fit	string	No	Resize fit: cover, contain, fill, inside, outside
rotate	number	No	Rotation in degrees
watermark	file	No	Watermark image overlay

Content-Type: multipart/form-data · Response: binary

Returns the converted image with Content-Disposition attachment headers.

Example

curl -X POST "https://your-domain.com/api/v1/convert/images" \
  -F "file=@photo.jpg" \
  -F "format=webp" \
  -F "quality=85" \
  -o output.webp

POST

/api/v1/convert/documents

Convert documents

Convert between document formats (PDF, DOCX, TXT, RTF, XLSX, etc.). Max 200MB per file.

Parameters

Name	Type	Required	Description
file	file	Yes	Source document
format	string	Yes	Target format

Content-Type: multipart/form-data · Response: binary

Returns the converted document file.

Example

curl -X POST "https://your-domain.com/api/v1/convert/documents" \
  -F "file=@report.docx" \
  -F "format=pdf" \
  -o report.pdf

POST

/api/v1/convert/pdf

Images to PDF

Merge one or more images into a single PDF. Max 200MB per image.

Parameters

Name	Type	Required	Description
file	file	Yes	One or more image files (repeat field)
format	string	Yes	Must be "pdf"

Content-Type: multipart/form-data · Response: binary

Returns a PDF file.

Example

curl -X POST "https://your-domain.com/api/v1/convert/pdf" \
  -F "file=@page1.png" \
  -F "file=@page2.png" \
  -F "format=pdf" \
  -o combined.pdf

POST

/api/v1/convert/archive/create

Create a ZIP archive

Bundle multiple files into one ZIP. Total size up to 500MB.

Parameters

Name	Type	Required	Description
file	file	Yes	Files to include (repeat field)
filename	string	No	Output filename (default archive.zip)

Content-Type: multipart/form-data · Response: binary

Returns a ZIP archive.

Example

curl -X POST "https://your-domain.com/api/v1/convert/archive/create" \
  -F "file=@doc.pdf" \
  -F "file=@image.png" \
  -F "filename=bundle.zip" \
  -o bundle.zip

POST

/api/v1/convert/archive/extract

Extract ZIP contents

List and extract files from a ZIP archive. Max 500MB.

Parameters

Name	Type	Required	Description
file	file	Yes	ZIP archive file

Content-Type: multipart/form-data · Response: json

Returns JSON with archive metadata and entry list.

Example

curl -X POST "https://your-domain.com/api/v1/convert/archive/extract" \
  -F "file=@archive.zip"

Tools API

POST

/api/v1/tools/compress

Compress an image

Reduce image file size. Supports JPG, PNG, WebP, AVIF, TIFF. Max 200MB.

Parameters

Name	Type	Required	Description
file	file	Yes	Image to compress
quality	number	No	Quality 1–100 (default 70)

Content-Type: multipart/form-data · Response: binary

Returns compressed image. Headers X-Original-Size and X-Compressed-Size included.

Example

curl -X POST "https://your-domain.com/api/v1/tools/compress" \
  -F "file=@input.jpg" \
  -F "quality=70" \
  -o output.jpg

POST

/api/v1/tools/archive/create-zip

Create ZIP archive

Same as convert/archive/create. Total up to 500MB.

Parameters

Name	Type	Required	Description
file	file	Yes	Files to bundle (repeat field)
filename	string	No	Output filename

Content-Type: multipart/form-data · Response: binary

Returns a ZIP file.

Example

curl -X POST "https://your-domain.com/api/v1/tools/archive/create-zip" \
  -F "file=@a.pdf" \
  -F "file=@b.png" \
  -o my-archive.zip

POST

/api/v1/tools/archive/extract

Inspect or convert archives

Inspect ZIP contents or convert TAR/TGZ/TBZ2 to ZIP. Max 500MB.

Parameters

Name	Type	Required	Description
file	file	Yes	Archive file (ZIP, TAR, TGZ, TBZ2)

Content-Type: multipart/form-data · Response: json

ZIP returns JSON entry list; other formats may return a converted ZIP binary.

Example

curl -X POST "https://your-domain.com/api/v1/tools/archive/extract" \
  -F "file=@archive.zip"

POST

/api/v1/tools/rar-to-zip

Convert RAR to ZIP

Convert a RAR archive to ZIP format. Max 500MB.

Parameters

Name	Type	Required	Description
file	file	Yes	RAR archive file

Content-Type: multipart/form-data · Response: binary

Returns a ZIP file.

Example

curl -X POST "https://your-domain.com/api/v1/tools/rar-to-zip" \
  -F "file=@archive.rar" \
  -o archive.zip

Integrations API

POST

/api/v1/integrations/import

Import from cloud URL

Download a file from Google Drive or Dropbox and store it for processing. Max 100MB per file.

Parameters

Name	Type	Required	Description
url	string	Yes	Public Google Drive or Dropbox share URL

Content-Type: application/json · Response: json

Returns JSON with file metadata and storage reference.

Example

curl -X POST "https://your-domain.com/api/v1/integrations/import" \
  -H "Content-Type: application/json" \
  -d '{"url":"https://www.dropbox.com/s/..."}'

Roadmap

10 endpoints available · OpenAPI spec at /api/v1/openapi.json (authenticated)