Getting Started

This guide walks you through your first Closed Caption Converter session, from signing up through to running your first conversion. Closed Caption Converter is available as a web application, an API, and a CLI tool. All three share the same underlying conversion engine, the same format support, and the same filter library — only the interface differs.

Creating an Account

To use the Closed Caption Converter web application or API, you will need to create an account at app.closedcaptionconverter.com. A free 7-day trial, giving you full access to all features including filters and access provider integrations. API keys and server-side API jobs require an active subscription after the trial.

Once registered you will be taken to the Subtitle Converter workspace — the default landing page after sign-in. The left Workspaces sidebar provides access to all areas of the web application:

Workspace	Purpose
Subtitle Converter	Local browser-based format conversion and preview
API Playground	Submit and test POST /jobs and GET /jobs (with job ID) requests
Job Status Dashboard	View, filter, and manage API job history
Access Providers	Configure BYOK integrations for transcription, translation, and delivery
Job Presets	Save and manage reusable Job Descriptions
Account & Billing	Subscription, Stripe billing portal, and API keys

The top bar includes Chat (AI assistant), Support (user guide and contact), and Exit (sign out). The CLI can be deployed for offline use with a locally-provided license file, while the web application and API require an online account.

Using the Web Application

The web application runs in your browser. You still need an internet connection to authenticate and load the application, but caption files are never uploaded to any server during normal conversion work on the Subtitle Converter workspace. Decoding, filtering, and encoding are performed locally using WebAssembly. This makes the web application suitable for sensitive content and controlled environments that permit browser access to the application itself.

To convert a file, click Select File and choose one or more caption files from your computer. Closed Caption Converter will automatically attempt to detect the source format based on the file extension and content. You can then select your Target Profile (the output format), adjust the Frame Rate, and optionally enable any Filters you want applied before encoding.

Once you are satisfied with the configuration, click Convert to process the file. The output file will be available for download immediately. No data leaves your device at any point.

Selecting Profiles

The Source Profile tells the engine how to read your input file. In most cases the web application will detect this automatically, but you can override the selected profile by opening the source profile dropdown and choosing from the full list. The Target Profile determines the output format. You can pick any encode-capable profile from the dropdown regardless of what the source format is.

For a complete list of all supported source and target profiles, see Profiles & Formats.

Configuring Filters

Closed Caption Converter exposes most processing controls through the Advanced Tools panels beneath the profile selectors. Open the panels you need, such as Timing & Sync, Automatic Format, Automatic Reading Speed, Event Gap, Search & Replace, Caption Style, or Reposition, and configure them inline. Some panels are true format-agnostic filters, while others only appear when the selected source or target profile supports them.

For a full description of every filter and its settings, see Filters.

Encoding & Decoding Options

Many profiles expose format-specific configuration that controls how they read or write files — for example the character encoding of a text file, the channel assignment for SCC data, or language metadata for EBU-STL. These options appear automatically when you select a profile that supports them. See Encoding & Decoding Options for more detail.

Your First API Job

If you plan to use the Closed Caption Converter API, begin by opening Account & Billing in the left sidebar, selecting the API Keys tab, and clicking Generate Key. Your API key is sent in the x-api-key request header. API key management is not available during the free trial — activate your subscription first.

The fastest way to test the API from the browser is the API Playground workspace, which supports submitting jobs, polling results, and exporting a Postman collection.

The base URL for the API is:

https://api.closedcaptionconverter.com

A minimal conversion job can be submitted with a single POST request containing a Job Description. See API — Getting Started for a full walkthrough including authentication, your first request, and the Postman collection.

Your First CLI Job

The CLI is a single binary executable available for macOS, Windows, and Linux. It accepts a Job Description JSON file (the same format used by the API) and processes caption files locally on your machine. No internet connection is required for local conversion work once the binary and license are in place, although stored presets still require connectivity because they are resolved from the server.

See the CLI page for download instructions, installation, and your first conversion command.

Next Steps

Once you have completed your first conversion, explore the following areas to get more out of Closed Caption Converter:

Topic	Description
API Playground	Test API jobs interactively from the browser.
Profiles & Formats	Browse the complete list of 30+ supported source and target formats.
Filters	Learn how each filter works and when to use it.
Encoding & Decoding Options	Understand the format-specific options exposed by each profile.
Access Providers	Set up BYOK integrations for transcription, translation, storage, and platform delivery.
API — Job Types & Descriptions	Understand the full Job Description schema and all supported job types.
API — Presets	Save frequently-used configurations as named presets for reuse in code.
CLI	Deploy the CLI for on-premise and offline workflows.