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All Subtitle Tools

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31+ editors & utilities86 format converters11 core subtitle formats + YouTube JSON3 inputFree · In-browser

Convert

(3)

Switch between formats, fix encoding, and change frame rate.

Batch Subtitle Converter

Batch convert supported subtitle files to SRT, VTT, ASS, LRC, or TXT at once. Completely free, no registration required.

Fix Corrupted Subtitles & Character Encoding

Fix encoding mismatches and convert subtitles between UTF-8, UTF-8 with BOM, UTF-16 LE/BE with BOM, GB18030/GBK, BIG5, Shift-JIS, EUC-KR, Windows-1252, and ISO-8859-1.

Subtitle Frame Rate Converter

Convert subtitle frame rates between 23.976, 24, 25, 29.97, 30, 48, 50, 59.94 and 60 fps. Fix NTSC/PAL speedup sync issues. Free, browser-based, no uploads.

Edit & Clean

(6)

Fix text, styling, and layout in seconds.

Subtitle Format Cleaner

Clean up subtitle files in one click. Remove HTML tags, ASS override blocks, hearing-impaired annotations, and duplicate lines. Free browser tool.

Subtitle Editor

Edit subtitle files online. Modify text, adjust timecodes, add and delete cue rows in a table editor. Export to SRT, VTT, or ASS. Free, browser-based, no uploads.

Subtitle Styler

Style your subtitles with custom colors, fonts, positions, and outlines. Export as ASS, VTT, or SRT with styling preserved where the format supports it. Free, browser-based, no uploads.

Smart Subtitle Cleaner

Smart-clean subtitles with language-aware rules for Chinese, Japanese, Korean, English, Spanish, French, and German. Normalize punctuation, quotes, dashes, and CJK spacing. Free.

Subtitle Find & Replace

Search and replace text in subtitle files with regex, whole-word, and case-sensitive options. Preview all matches before replacing. Free, browser-based, no uploads.

Smart Line Break Optimizer & Text Balancer

Balance subtitle line lengths and optimize line breaks based on natural grammar pauses. Set max characters per line (CPL). Free browser tool.

Sync & Time

(4)

Re-time and adjust the subtitle clock.

Subtitle Sync & Timing Calibration

Fix out-of-sync subtitles online. Shift timestamps forward or backward, or use 2-point calibration for linear drift. Free browser-based tool.

Subtitle Speed Adjuster

Scale all subtitle timestamps with a speed factor from 0.1 to 10. Free browser tool.

Partial Subtitle Sync

Adjust timing for only a range of subtitle cues instead of the entire file. Fix subtitles that drift out of sync partway through. Free, browser-based, no uploads.

Adjust subtitle timing to align with common streaming and broadcast guidelines (such as minimum 2-frame gap requirements). Enforce a minimum gap between adjacent cues set by milliseconds or frame count.

Merge & Split

(5)

Combine, split, and restructure files.

Subtitle Merger

Merge two subtitle files into a single bilingual (dual-language) subtitle or combine them sequentially. Free, browser-based, no upload required.

Subtitle Splitter

Split subtitle files by cue count, number of parts, or at a specific time. Free browser tool.

Bilingual Subtitle Merger

Merge two subtitle files in different languages into a single bilingual subtitle file with aligned timestamps. Free browser tool.

Auto-Merge Short Cues

Automatically merge fragmented subtitle cues from Whisper and YouTube. Combine adjacent short cues separated by tiny pauses into clean, readable lines. Improve on-screen readability.

Style-Safe Subtitle Splitter

Split long subtitle lines at a chosen position while preserving HTML and ASS override tags. Tags are closed and reopened so both halves render.

Quality & QA

(5)

Check, diff, and auto-fix issues.

Subtitle Quality Checker

Analyze subtitle files for quality issues: reading speed (CPS), line length, overlapping cues, timing gaps, and empty text. Get a quality score. Free.

Subtitle Diff Tool

Compare two subtitle files side by side and find every difference. Word-level highlighting, similarity score, and timing changes. Free, browser-based, no uploads.

Auto Fix Subtitles

Automatically detect and fix subtitle problems: overlapping cues, high reading speed (CPS), empty lines, tiny cues, and invalid timestamps. Preview changes.

Subtitle QA Report

Generate a professional subtitle QA report with an overall quality score. Analyze timing, reading speed, consistency, style, content, and encoding. Export as text, Markdown, or HTML.

Subtitle Statistics

Get detailed subtitle statistics: cue count, characters, words, average and max CPS, duration, longest and shortest lines, language detection. Free subtitle statistics tool.

AI Tools

(3)

Translate, rewrite, and annotate with AI.

AI Subtitle Translator

Translate subtitles into 19 built-in target languages using AI. Bring your own API key for OpenAI or an approved OpenAI-compatible provider.

AI Subtitle Annotator

Add pronunciation guides to Chinese and Japanese subtitles. Generate pinyin for Chinese characters, furigana for kanji, or romaji. AI-powered, browser-based.

AI Subtitle Rewriter

Use AI to rewrite subtitles: improve naturalness, fix grammar, shorten long lines, expand terse text, simplify, or rewrite conversationally. Bring your own API key.