RST vs SRT
A detailed comparison of reStructuredText and SubRip Subtitle — file size, quality, compatibility, and which format to choose for your workflow.
reStructuredText
Documents & TextRST (reStructuredText) is a lightweight markup language used in Python documentation.
About RST filesSubRip Subtitle
Documents & TextSRT is the most widely used subtitle format with simple timestamps and text.
About SRT filesStrengths Comparison
RST Strengths
- Rich directives for admonitions, code, math, and custom elements.
- Cross-references work within and across documents.
- Sphinx ecosystem offers best-in-class Python docs output.
- Standardized as part of Python PEP infrastructure.
- Plain text, version-controllable.
SRT Strengths
- Trivially simple — every video player reads SRT sidecar files automatically.
- Plain text — editable in Notepad, grep-able, diff-friendly.
- Universal tooling — OCR, translation, and timing apps all speak SRT natively.
- Tiny file sizes — a 2-hour movie of subtitles is usually under 100 KB.
Limitations
RST Limitations
- Syntax denser than Markdown — higher learning curve.
- Less widely adopted than Markdown outside Python world.
- Multiple directive dialects (Sphinx, Docutils, custom) create fragmentation.
- MyST (Markdown + Sphinx) has pulled many Python projects toward Markdown.
SRT Limitations
- No formal standard — edge cases (nested tags, encoding, line count) vary.
- No styling beyond basic HTML — no positioning, no colors beyond italic/bold.
- Character encoding ambiguity — some SRTs are Windows-1252, some UTF-8, some UTF-16.
- Cannot represent multiple speakers, sound effects, or precise positioning like SSA/ASS can.
Technical Specifications
| Specification | RST | SRT |
|---|---|---|
| MIME type | text/x-rst | application/x-subrip |
| Extension | .rst | .srt |
| Toolchain | Docutils, Sphinx, Read the Docs | — |
| Encoding | UTF-8 | Typically UTF-8 (modern) or CP1252 (legacy) |
| Related formats | MyST (Markdown + RST directives) | — |
| Structure | — | Numbered blocks: index → timecodes → text → blank line |
| Timecode format | — | HH:MM:SS,mmm --> HH:MM:SS,mmm |
Typical File Sizes
RST
- API reference page 5-50 KB
- Sphinx project chapter 20-100 KB
- Full library documentation 500 KB - 10 MB
SRT
- 1-hour TV episode (English) 30-80 KB
- 2-hour movie (English) 50-120 KB
- Anime episode with stylized Japanese 80-200 KB
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Convert between RST and SRT online, free, and without installing anything. Encrypted upload, automatic deletion after 60 minutes.
Frequently Asked Questions
RST (reStructuredText) is a document format used to store paginated text, with optional formatting, tables, images, hyperlinks, headers and footers. It sits in the documents & text family and is typically associated with a specific office suite or publishing pipeline that defined the format and ships the canonical reader.
RST (reStructuredText) is a document formato used to store paginated text, com optional formatoting, tables, images, hyperlinks, headers e footers. It sits no documents & text family e is tipicamente associated com a specific office suite ou publishing pipeline that defined the formato e ships the canonical reader.
Modern office suites — Microsoft Word, Google Docs, LibreOffice Writer, Apple Pages — open most RST files with reasonable fidelity. If your installed software does not support RST, convert to DOCX or PDF first using KaijuConverter; both open in virtually every reader, including free online viewers.
Modern office suites — Microsoft Word, Google Docs, LibreOffice Writer, Apple Pages — abrir most RST arquivos com reasonable fidelity. If your installed software does not support RST, converter to DOCX ou PDF first usando KaijuConverter; both abrir in virtually every reader, including grátis online viewers.
Upload the RST to KaijuConverter and pick DOCX, PDF, ODT, RTF, HTML, Markdown, or plain text. Our pipeline runs LibreOffice headlessly plus pandoc for text formats — the same engines behind professional document pipelines. Styles, tables, images, and hyperlinks survive the conversion intact.
Yes, to a high degree. Standard fonts, headings, lists, tables, images, hyperlinks and page structure transfer cleanly. Custom fonts substitute to the closest match if not embedded; obscure layout features unique to RST (frames, legacy macros) may flatten to static content in the target format.