Gaupol

Gaupol is a desktop editor for creating, translating, timing and correcting text-based subtitle files. It suits Linux users who want a free, GPL-licensed workflow with integrated or external video playback. Windows users should approach it cautiously because the current release path is Linux-focused and the last Windows build has a disabled player.

Overview

Gaupol keeps the core subtitle workflow in one application: write or translate dialogue, align timing to video and correct common errors. It works with multiple subtitle formats and exports to SRT and VTT, making it suitable for projects that must deliver standard files to different playback or publishing systems.

The project also includes aeidon, a separately installable Python package for reading, writing and manipulating text-based subtitle files. That separation is useful for users who want to build repeatable processing around subtitle documents, but it does require an additional installation outside the main editor.

Video reference is built in, and Gaupol can launch an external player when that better fits a user's setup. The integrated player relies on GStreamer. Additional GStreamer plugins are recommended for broader container and codec support, so playback capability can depend on how the Linux system is configured.

Key features

• Subtitle creation and translation: Edit text-based subtitle files, translate dialogue and adjust timings against video. This covers the central work of individual subtitlers and small localization projects without splitting tasks among separate tools.
• Error correction: Gaupol is designed to correct common subtitle mistakes, a practical safeguard when cleaning existing files or preparing a translated version.
• Format flexibility: Support for multiple subtitle formats, plus SRT and VTT export, helps when a project moves between source files and widely accepted delivery formats.
• Video playback choices: Use the integrated GStreamer player or launch an external player. The choice is valuable when the internal player lacks a needed codec, although expanding GStreamer support may involve installing more plugins.
• Python subtitle library: The aeidon package can be installed separately for programmatic reading, writing and manipulation of subtitle files. It is a meaningful option for technical users who need library-level access rather than only a graphical editor.
• Optional spell-check and encoding support: The installation guide identifies libspelling for spell-checking and charset-normalizer for character-encoding auto-detection as optional dependencies. These capabilities therefore depend on adding those components.

Pricing

Plan	Price	What it includes
Gaupol	free	Free Software under the GNU General Public License (GPL) on Linux

There is no paid tier, subscription, quota or free-trial clock to manage. The GPL license also permits use without a purchase, while support is available through the project's documentation, discussions and issue tracker. Users who need a commercial support contract or a different licensing model should look elsewhere.

Platforms

Gaupol is available for Linux. The maker offers a Flatpak release, source code and packages for most popular Linux distributions, giving Linux users several installation routes. Windows installers are no longer built; version 1.3.1 is the latest Windows release, and its built-in video player is disabled. That makes Windows a legacy option for editing rather than a fully maintained platform, particularly for timing work that depends on in-app playback.

Who it's for

Gaupol is a strong fit for Linux-based subtitlers, translators and video projects that need a focused desktop editor with no licensing fee. It is also relevant to technically minded users who can take advantage of aeidon or manage optional dependencies such as GStreamer plugins, spell-check and encoding support.

It is less suitable for Windows users seeking a current installer and working integrated player, or for teams that expect a hosted service, machine transcription or account-based collaboration. Its strengths are file editing, timing and format conversion rather than a broader online production platform.

Pros and cons

Pros

• Completely free GPL software: There is no paid plan, trial expiry or subscription renewal.
• Complete core workflow: Creation, translation, timing and common-error correction are handled in one editor.
• Practical interchange: Multiple formats with SRT and VTT export cover common delivery requirements.
• Flexible playback: An integrated player and external-player launching give Linux users alternatives for timing reference.
• Automation potential: The separately installable aeidon library supports programmatic subtitle-file manipulation.

Cons

• Linux-first maintenance: Windows installers have stopped, and the latest Windows build disables its built-in player.
• Playback may need setup: Wider codec and container support depends on additional GStreamer plugins.
• Optional capabilities require dependencies: Spell-check and encoding auto-detection rely on separately installed components.
• No hosted workflow: Gaupol is a desktop tool, not an online service with published cloud quotas or collaboration plans.

Alternatives

Choose Editsub instead if you need Linux, macOS, Windows or web access and can work within its free limit of 10 subtitle files per month; its Pro plan adds 1,500 credits monthly for $48.00 per year.

Jubler is another free desktop subtitle editor for Linux, macOS and Windows, with VLC required for video preview and audio waveform.

Pick SRTGen when a web or API workflow is preferable and a free tier with SRT, VTT and TXT export, a five-minute screen-recording limit and 2 GB storage is sufficient.

Subtitle Edit is a free, open-source editor spanning Windows, macOS and Linux.

Aegisub is a free, open-source subtitle editor for Linux, macOS and Windows.

GNOME Subtitles is a GPL-licensed subtitle editor for Linux.

Choose Subvideo.ai for a web workflow with guest uploads and a free account offering three uploads per day and free subtitle exports including SRT.

VideoLocalize is a web/API option with a free tier, including one user account, two jobs, four-minute videos and 1 GB storage.

Browse the broader Subtitle Software category for more options.

Verdict

Choose Gaupol if you are a Linux user who wants a capable, format-flexible subtitle editor with video timing and no cost or subscription. Its GPL license, desktop workflow and aeidon library make it especially appealing for independent subtitling and technical automation. Look elsewhere if you need a maintained Windows release, a working Windows video player or a web-based collaborative service.