Timestamp validation
Check timestamp syntax, reversed ranges, zero-duration cues, overlaps and minimum gaps. The checker understands standard SRT timestamps and WebVTT timing.
SRT VALIDATOR
SRT validator and SRT checker online.
A subtitle file can open normally and still contain timing, numbering, overlap, readability or encoding problems. Use the SRT Subtitle Fixer to inspect those issues locally, review safe repairs and download a cleaned file.
FREE CHECKER
Open SRT checker →Validate your subtitle file now.
SRT and WebVTT. No account. Browser-local processing.
Subtitle structure
Inspect SRT numbering, empty cues, missing separators and recoverable malformed blocks. Safe normalization can sort cues and restore clean numbering.
Readability checks
Measure characters per second, line length, line count and cue duration against the active quality profile or your custom limits.
File diagnostics
See detected text encoding, BOM status, line-ending style, final-newline state and replacement-character warnings before delivery.
Overlap checking
Find cues whose display times collide, including overlaps discovered after chronological sorting rather than simply trusting file order.
Browser-local
Your subtitle file is read in the browser. The tool is designed so subtitle contents do not need to be uploaded to a processing server.
COMMON SRT PROBLEMS
What usually needs fixing?
Why is my SRT not importing?
Typical causes include malformed timestamps, a WebVTT header or dot-style timestamps inside an SRT, broken cue separators, empty cues, invalid numbering, or reversed timing. The destination application can be more strict than a media player.
What is a good CPS limit for subtitles?
Reading-speed limits vary by workflow. Practical subtitle tools commonly expose a configurable range around 17–20 characters per second rather than treating one number as universal. Use the specification for your actual delivery.
Can an SRT validator repair the file?
Mechanical problems such as numbering, sorting, empty-cue removal, some overlap handling and supported tag balancing can be repaired conservatively. Wording and editorial choices should remain for human review.
Does an SRT validator change subtitle text?
The checker is designed to keep dialogue unchanged. Its repair workflow focuses on mechanical file and timing structure rather than rewriting your captions.
MORE HELP
Fix subtitle timing →Subtitle timing is a different problem.
When every caption is consistently early or late—or gradually drifts—use the timing workflow.