Auto Fix Subtitles
Automatically detect and repair timing overlaps, high CPS, empty cues, and other common subtitle errors in one click.
Drag & drop your subtitle file here
Drag and drop subtitle files here or click to browse
What Auto Fix Can Repair
Engineered for video editors and localization teams. Helps enforce common subtitle timing rules and formatting.
Auto Fix Subtitles Live Execution Demo
In-Memory Processing
File parsing, mutations, and time shifts for standard tools run in browser memory without sending subtitle files to our servers.
Millisecond Precision
Millisecond-accurate timecode parsing and arithmetic prevent synchronization drift across desktop and web players.
Fault-Tolerant Engine
Automatic multi-encoding detection and syntax sanitization gracefully handle malformed cues and unexpected linebreaks.
Who Needs Auto Fix?
Real-world scenarios across video post-production, course transcription, and global localization.
Broadcast & Streaming Delivery
Automatically fix overlapping cues and high-CPS lines before delivering subtitles to Netflix, Amazon, or broadcast QC.
Fansub & Translation Teams
Clean up timing issues introduced during translation or manual editing so the final file plays smoothly.
Post-Production Editors
Run Auto Fix as a final QA pass before exporting subtitles for delivery. Fix overlaps, empty cues, and timing errors in seconds.
Content Creators & YouTubers
Fix subtitles generated by speech-to-text tools that often produce overlapping or too-fast cues.
Educators & E-Learning
Improve subtitle readability in online courses by fixing high CPS and merging tiny cues.
Accessibility Compliance
Use readability checks and cleanup to reduce overly fast cues and timing overlaps before accessibility review.
How It Works
Streamlined end-to-end processing pipeline engineered for speed and precision.
Upload your subtitle file
SRT, VTT, ASS, SSA, LRC, SBV, TTML, SCC, STL, and SMI are all supported.
Format Analysis
The Auto Fix engine scans your subtitles and reports how many issues were found in each category.
Configuration
Toggle individual fix rules on or off to control exactly what gets repaired.
Processing
Click Fix to apply the selected rules and preview the corrected result.
Verify & Export
Download the corrected subtitle file or run another pass with different rules.
Why Choose AllSubConverter?
Client-Side Privacy
Standard tools run in your browser so standard files are not uploaded to our servers.
Fast Local Parsing
Optimized processing engine parses and converts files directly in your browser.
Generous Batches
Up to 50 MB per file, 200 files or 1 GB total per batch.
Universal Compatibility
Runs in modern browsers across Windows, macOS, Linux, iOS, and Android.
More Subtitle Tools
Frequently Asked Questions
Auto Fix detects and repairs eight categories: overlapping cues, high reading speed (CPS), empty subtitle entries, tiny cues below a duration threshold, inconsistent punctuation, non-standard quotes, duplicate consecutive cues, and invalid timestamps where end comes before start.
No. All fixing happens entirely in your browser using JavaScript. Your subtitle files never leave your device, making Auto Fix safe for confidential or unreleased content.
When two cues overlap in time (the next cue starts before the current one ends), Auto Fix trims the first cue's end time to the start of the second, ensuring only one subtitle block displays at a time.
Auto Fix shows issue counts and lets you toggle each rule before applying it. Nothing is modified until you click Fix; review the preview and keep your original file if you want to compare results.
CPS measures reading speed: how many characters appear per second of a subtitle cue. Common readability guidelines typically recommend around 15-20 CPS. Auto Fix can extend the duration of high-CPS cues to bring them within a comfortable reading range.
Yes. Every fix rule is an independent toggle. You can apply only overlap fixing, only CPS adjustment, or any combination. The preview shows the count of issues each rule would repair.
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