Video Subtitles and On-Screen Text: A Practical Guide

Video subtitles, whether burned into the picture or delivered as a file the viewer switches on, make your content work for people watching without sound, for viewers who don't speak the language, and for deaf and hard-of-hearing audiences. Bad subtitles, with long lines, late timing and broken Arabic letters, do more harm than good. This guide covers open versus closed captions, how an SRT file is built, the usual norms for line length and reading speed, Arabic typography and right-to-left issues, translation quality, accessibility and other on-screen text.

Key terms

• Subtitles: the dialogue as text, usually in another language, for viewers who can hear the audio but don't understand it.
• Captions: a transcript of the dialogue in its original language, plus descriptions of important sounds such as [soft music] or [applause] and speaker labels where needed. They are aimed primarily at deaf and hard-of-hearing viewers.
• SDH (subtitles for the deaf and hard of hearing): a combination of both, translating the dialogue and describing sounds as well.
• On-screen text: titles, name straps and key messages in ads. It is part of the design, not a transcript of the dialogue.

If you are just starting out, Video Editing: The Complete Beginner's Guide shows where subtitling fits in the overall workflow.

Open or closed captions?

Open captions are burned into the picture at export and always appear. Closed captions are a separate text file uploaded with the video, which the viewer can turn on or off.

Many creators use both: burned-in subtitles for vertical clips on social platforms, and separate files for the YouTube version and website pages. Separate files have another advantage: some players let viewers enlarge the text or change its color to suit their needs.

How an SRT file works

SRT is the most widely used format for separate subtitle files. It is plain text you can open in any text editor, and each subtitle block has four parts:

1. A sequence number, starting at 1 and going up with each new subtitle.
2. A timing line: the in time, an arrow, then the out time, written as hours, minutes and seconds with milliseconds after a comma, for example 00:00:01,000 --> 00:00:03,500.
3. The subtitle text, on one or two lines.
4. A blank line separating it from the next block.

Practical notes:

• Save the file as UTF-8 so Arabic displays correctly; other encodings show garbled characters in some players.
• WebVTT is very close to SRT and is used by web players. It starts with a line reading WEBVTT and uses a full stop instead of a comma before the milliseconds.
• Most editing programs can import and export subtitle files, and some offer automatic transcription. Treat that as a useful first draft that needs careful human review, especially with Gulf and Egyptian dialect and with names.
• Most major platforms accept an uploaded subtitle file, but supported formats and naming rules differ, so check each platform's current help pages.

Timing, line length and reading speed

Professional subtitling style guides differ slightly in their numbers, but common practice sits around these values:

• Two lines maximum per subtitle.
• About 37 to 42 characters per line, including spaces, with a similar range often used for Arabic.
• A reading speed of roughly 15 to 17 characters per second for adults, and slower for children's content.
• A minimum duration of about one second and a maximum of 6 or 7 seconds for a single subtitle.
• A gap of at least two frames between consecutive subtitles, so the eye registers that the text has changed.

Illustrative calculation: a 60-character sentence at 15 characters per second needs about 4 seconds on screen. If the speaker says it in 2 seconds, shorten the text rather than rushing the reader.

On timing: bring each subtitle in as the speech starts and take it out shortly after it ends, and try not to let one subtitle run across a picture cut, because a shot change makes the eye start reading again.

Where to break a line

Break lines at natural pauses, and keep words that belong together on the same line:

• Don't separate a preposition from the noun that follows it.
• Don't split an article from its noun, or an adjective from the word it describes.
• Don't end a line on a word such as "that", "which" or "and" that leans on what comes next.

Arabic subtitles: type and direction

Choosing and styling the font

• Choose a clear font designed for screens, with open letterforms, such as Noto Sans Arabic or IBM Plex Sans Arabic, or the brand typeface if it stays legible at small sizes. Avoid decorative calligraphic styles such as Diwani or Thuluth for subtitles.
• Use a medium or bold weight; thin weights disappear over bright or busy backgrounds.
• Size Arabic up slightly when it sits next to English, since Arabic tends to look smaller than Latin text at the same nominal size.
• Add something that guarantees legibility: a thin outline, a soft shadow or a semi-transparent box behind the text.
• Use diacritics only where needed to avoid ambiguity; too many clutter the line, and some fonts render them poorly.

Typography and Arabic Fonts in Design goes deeper into choosing and setting Arabic type.

Right-to-left pitfalls

• Disconnected or reversed letters appear when software doesn't support Arabic shaping. Enable the Middle Eastern text engine in the type preferences where the program offers one, or use a tool with genuine Arabic support. Avoid tools that "flip" Arabic text, because the result breaks as soon as you edit it.
• Punctuation at the wrong end: in some players a full stop or question mark shows up at the start of the line instead of the end. Check in the actual player; an invisible control character called the right-to-left mark (RLM) can fix it in some cases.
• English words and numbers inside an Arabic sentence can change the display order. Keep them short, check every line that contains them, and avoid starting an Arabic line with a Latin word where you can.
• Digits: choose Western digits (1, 2, 3) or Eastern Arabic digits and stick to one convention for the whole project, following the brand guidelines.
• Bilingual subtitles on the same screen double the amount of text. Use them only when necessary, decide which language leads, and keep the order of the two lines fixed throughout.

Translation quality

• Translate meaning, not words. Subtitles are condensed by nature and can't carry every spoken word.
• Choose the register deliberately. Modern Standard Arabic suits a broad Arab audience, while a brand may choose a local dialect for social content aimed at one market. What matters is that the choice is intentional and consistent.
• Keep a glossary that fixes how the brand, product names and technical terms are written in Arabic, so the same name doesn't appear three different ways.
• Adapt cultural references: idioms, humor, currencies and units, such as turning a dollar example into dirhams or riyals where the context allows.
• Review the translation against the picture, not just in a spreadsheet, and use a native speaker of the target language.
• Re-time after translating, because sentence length differs between Arabic and English.
• Proofread Arabic spelling: hamza placement, taa marbuta versus haa, and alif maqsura versus yaa are the errors that show up most in video subtitles.

Subtitles and accessibility

• Describe important sounds in captions: music, laughter, a knock at the door, whenever they affect understanding.
• Identify the speaker when the picture doesn't make it clear, such as a voice from off screen.
• Mind contrast, size and duration; a subtitle nobody can read does nothing.
• Don't cover what matters: faces, the product and other text. If a name strap appears at the bottom, move the subtitle to the top for that moment.
• Allow for vertical-platform interfaces. Buttons, the account name and the caption cover the bottom and side of the screen, and each platform publishes safe zones worth checking in its current help pages.
• Publish a written transcript on the web page where you can. It helps users and search engines alike, as Web Accessibility: A Website Everyone Can Use explains.

Other on-screen text

• Name straps (lower thirds): name and title in one consistent style across the video, in both languages where needed. A practical rule for duration: leave them up long enough to read twice at a relaxed pace.
• Key messages in ads: price, offer and how long it runs, plus any legal wording or disclosures the relevant authority requires. They must actually be readable, not merely present.
• Safe margins: keep text well away from the frame edges, because some screens and platforms crop or cover them.
• Brand consistency: fonts, colors and motion should follow your brand guidelines.
• Avoid stacked text layers: if a spoken line already appears as large designed text, don't add a subtitle underneath repeating it.

Animating the text itself with deliberate rhythm is its own topic, covered in Kinetic Typography and Logo Animation.

Pre-publishing checklist

• Did you choose burned-in subtitles or a separate file for each platform, or both?
• Is the SRT file saved as UTF-8 and in sync from start to finish?
• Does every subtitle stay within two lines at a comfortable reading speed?
• Are Arabic letters joined and punctuation in the right place?
• Has a native speaker reviewed the translation against the picture?
• Are brand and product names written according to the glossary?
• Are subtitles clear of faces, other text and platform interface elements?
• Did you export a textless version so other languages can be added later? Video Export Settings covers the options.