SRT vs ASS: Which Subtitle Format Should You Choose?

When you generate subtitles, you'll be asked to choose a format. The two options Subify supports, SRT and ASS, produce files that look very similar at first glance but behave very differently. This guide breaks down what each format can and cannot do, so you can pick the right one for your project.

What Is SRT?

SRT (SubRip Subtitle) is the simplest and most widely compatible subtitle format. Each entry in an SRT file contains a sequence number, a timestamp for when the subtitle should appear and disappear, and the subtitle text itself. There is no styling information, no fonts, colours, or positioning. The text renders in whatever default the player chooses.

This simplicity is SRT's strength. YouTube, Vimeo, Netflix, VLC, MPC-HC, and virtually every media player and platform on the market supports SRT files. If you're uploading to a platform and aren't sure which format to select, SRT is the safe default. It's also the only format available on the Free tier.

What Is ASS?

ASS (Advanced SubStation Alpha) is a more advanced format that supports extensive styling. An ASS file can specify custom fonts, font sizes, primary and outline colours (with a hex colour picker), background boxes with adjustable opacity, nine different alignment positions, shadows, and toggle switches for bold, italic, underline, and strikethrough.

ASS also unlocks Subify's specialised display modes. Beyond the standard Default, Single Line, and Single Word modes, ASS supports Karaoke, a display mode that highlights words one at a time as they're spoken, with a colour track that follows the audio. This is useful for music videos, lyric videos, and language learning content.

Feature Comparison

When to Use SRT

Choose SRT when compatibility matters more than customisation. If you're uploading to YouTube, sharing with collaborators, or distributing widely across platforms, SRT is the format that works everywhere. It's lightweight, easy to edit in any text editor, and supported by every subtitle-aware player.

SRT is also the right choice when you need a quick turnaround and don't need custom styling. Since it's available on all plans (including Free), you can start generating subtitles immediately without upgrading.

When to Use ASS

Choose ASS when you need control over how your subtitles look. If you're creating branded content where the font and colour palette matter, if you need karaoke-style word highlighting, or if you're producing content where precise positioning is important (avoiding on-screen graphics, for example), ASS gives you that control.

ASS is also the format to choose if you're working with subtitle editors like Aegisub or tools that support advanced styling. The files preserve all your customisation choices and can be edited further after download.

Which Subify Plans Include Each Format

SRT is available on every plan - Free, Solo, Audio Lite, Pro, Audio Plus, and Enterprise. ASS is available on all paid plans. If you're not sure whether you need ASS, start with the Free tier to test SRT generation. You can upgrade anytime to unlock ASS and the other paid features.

See our pricing page for full plan details and a feature comparison table.