Helphonic

Subtitle Editor & Converter

Edit subtitle text and timing, shift cues and convert SRT to WebVTT or VTT to SRT locally in your browser.

Unlimited Free Usage

Import a UTF-8 SRT or VTT file above, or paste subtitles below. Edit source text directly or load a cue-by-cue editor. Up to 500 cues. Styling, cue IDs, positions, NOTE and REGION blocks are not preserved.

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File contents and entered text stay on this device. Only access checks and non-content usage metadata go to Helphonic.

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Current limits

per operation

Files
1
Per file
1 MB
Total size
1 MB
Optional file
One optional 1 MB file
Text length
500,000 characters
Subtitles
500 cues
Text per subtitle
2,000 characters per cue.

Limits protect your device memory. Processing speed depends on your device.

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Processing limits

One optional 1 MB file; 500,000 characters; 500 cues; 2,000 characters per cue.
Limit comparison

How to increase limits

Compare the per-operation limits available after registration or with an active paid pass.

Free account

Registered user

Unlimited Free Usage

Files
1
Per file
1 MB
Total size
1 MB
Optional file
One optional 1 MB file
Text length
500,000 characters
Subtitles
500 cues
Text per subtitle
2,000 characters per cue.
Create a free account
All access passes

Unlimited operations during active validity, subject to abuse safeguards.

Files
1
Per file
1 MB
Total size
1 MB
Optional file
One optional 1 MB file
Text length
500,000 characters
Subtitles
500 cues
Text per subtitle
2,000 characters per cue.
View packages

The same limits may apply to every tier. Check before purchasing. Device safety limits still apply.

Frequently asked questions

Is my content sent to a server?

No. Entered text, imported files, generated passwords and invoice details are processed on this device. Helphonic serves the application and checks access, without receiving that content.

Is this tool free?

This tool starts with unlimited free usage for guests, registered users and active paid users. Administrators may configure allowances later. The current policy is displayed above; successful export counts as one operation if limits are enabled.

Will my work be saved?

No account storage or autosave is provided. Download or copy your result before leaving. Device safety limits apply even when usage is unlimited.

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How to use

Subtitle Editor & Converter

Learn how to use Subtitle Editor & Converter: step-by-step instructions, settings, export options, privacy, limits and troubleshooting.

Step-by-step instructions

  1. Paste subtitles or choose one UTF-8 SRT or VTT file.
  2. Click Load cue editor to edit individual start times, end times and captions, or edit the source directly.
  3. Choose SRT or WebVTT, optionally shift all times in seconds, then export and download.
Important details

Only timed text cues are retained. WebVTT styling, cue IDs, positioning settings, NOTE and REGION blocks are not preserved. Caption markup remains literal source text; it is never rendered as HTML on this page.

Times must stay non-negative and below 100 hours, with an end time after each start. Overlapping cues are permitted and are not automatically corrected.

The editor handles up to 500 cues. Changes are not saved; retain the original and test the exported file with your player.

Privacy and usage

Content stays in your browser. Helphonic receives only access checks and non-content operation metadata. Download or copy results before leaving; there is no account storage. Usage is initially unlimited for all audiences but remains configurable by an administrator.

Processing and privacy

Files and entered content are processed on your device in this browser tab. File contents and results are not uploaded to Helphonic or sent to analytics. The page still contacts Helphonic to load its tools, check access and confirm non-content usage information. Work is not saved to your account; download or copy results before leaving or reloading the page.

If an operation cannot finish

Use a current browser and smaller inputs if the tab runs out of memory. Some tools download a local processing library or model on first use, so an internet connection is needed even though your content stays on the device.

If the tool reports that access or limits changed, review the current policy and run it again. If usage confirmation is uncertain after an interrupted connection, a retry can count as another operation. Download completed work before reloading; this site does not keep a recovery copy.

About this tool

Paste SRT or VTT text, or import one UTF-8 subtitle file. Edit the source directly or load the cue-by-cue editor, set a positive or negative time shift, and export. Exporting applies the shift once; it does not change your original source.

Read the full Subtitle Editor & Converter guide (opens in a new tab)