When it comes to translating subtitles, you’re not just swapping words between languages. You’re shaping how your target audience experiences a story, an idea, or a lesson. 

As a translation or localization professional, you already understand the unique demands of this work: preserving tone, matching timing, and ensuring cultural nuances resonate with viewers across different languages.

Yet, with tight deadlines and increasing expectations for speed and quality, the challenges have only grown.

This guide covers everything you need to know to master the art of subtitle translation, from choosing the right tools and workflows to avoiding common pitfalls.

💪 Actionable tips
Whether you’re fine-tuning subtitles for a documentary, localizing a blockbuster movie, or adapting educational content, these insights will help you deliver translations that don’t just inform—but engage and inspire. We’ll also show you how you can use Lokalise to translate your subtitles fast.

The importance of translating subtitles

Translating subtitles into other languages is one form of video localization, as well as dubbing and voiceover. It’s a way to make your content culturally and linguistically relevant to new audiences and break down barriers. But it’s not just language barriers we’re talking about.

When you add source language captions to your video, you make it more accessible for anyone who is deaf or hard of hearing, or just anyone who doesn’t want to turn the audio on.

There are specific rules for closed captions to support people with hearing impairments. But subtitles do more than that—they help non-native speakers follow along and understand the story.

By adding subtitles in target languages, you can easily reach new audiences and markets. It’s a quick, affordable way to boost your content’s reach and impact.

What types of content need subtitles?

Translating subtitles isn’t just for big names like Netflix or Disney anymore. Now, marketing, content, and growth teams are using subtitle translation to tap into new markets and reach wider audiences.

Here are just a few types of videos that you may have available for subtitling:

• Marketing videos
• Tutorials
• Training course videos
• Webinars
• Product demos
• Support videos
• Explainer videos
• Guest interviews
• Speeches

Whether you’re looking to expand internationally or just connect with more viewers at home, adding subtitle translations can transform your video library into a powerful tool for growth.

🧠 Did you know?
If you’re localizing YouTube videos, having your subtitles available in multiple languages can help your SEO. It can give your older videos new life with minimal cost.

What to consider when translating subtitles

There are a few different things to keep in mind when translating subtitles. Firstly, you need to make sure to adapt the text properly.

People read slower than they listen, so subtitles need to be concise while still capturing the original message. For example, translating from English to Spanish can increase the text length by 20-25%, while translating to Swedish can expand it by up to 35%.

How to trim subtitle translations

To keep subtitles readable, it’s crucial to trim the text without losing its meaning. There are many ways to do this, but some common ways are:

• Editing out superfluous words (like fillers or repetition)
• Changing grammatical structures
• Merging two sentences into one
• Using antonyms to create shorter sentences

This can be quite tricky as the tone might slightly change. However, it’s on you as the translator to make the call where this makes sense for the sake of accuracy. Here are a few examples.

Techniques for adapting text in subtitle translations	Source text	Subtitle translation
Change of grammatical form	“She was taught long division by her teacher” (43 characters)	“Her teacher taught her long division” (35 characters)
Antonym translation	“I don’t think you’re right” (26 characters)	“I think you’re wrong” (20 characters)
Condensation	“Due to the extremely heavy rain, the event was unfortunately canceled.” (69 characters)	“Heavy rain canceled the event.” (30 characters)
Transposition	“In the library, a student found the lost book.” (43 characters)	“A student found the lost book in the library.” (42 characters)
Synonym translation	“The cat was extremely hungry after its long nap.” (52 characters)	“The cat was very hungry after its long nap.” (47 characters)

Length and spacing of subtitle translations

The standard is to stick to a maximum of two lines on the screen at a time, one if possible. This allows viewers to see the visual content, but also not be overwhelmed by reading.

The number of characters per line depends on the language used. However, many advise keeping to around 35 characters per line in most languages, or 16 characters per line in East Asian languages such as Chinese, Japanese, and Korean.

Timing

It’s also essential to ensure timing is synced correctly. Your subtitle should appear when the speaker starts talking and stop appearing soon after the speaker stops.

💡 Pro tip
A rough estimate of timing is to give 2 seconds per line of text, but this can be changed or reduced slightly after testing.

Quality assurance

We advise you to test your subtitles along with your video before publishing. It’s also a good idea to get a native speaker who is a subtitling expert to review them. They can check if it’s possible to read the line in the given time, and make sure the meaning is there.

Subtitling translation with Lokalise

There are plenty of subtitle translation software out there, but Lokalise stands out with features that can support you at any scale, whether you’re handling a small project or a larger one. No matter what your needs are, Lokalise has you covered.

SRT file support

Gone are the days of burning subtitles directly onto a video. The best way to add subtitles to a video is in a plain text file, which is separate from the video. 

Subtitle file formats like SRT file contain information regarding the subtitles, including the start and end time codes of the text, so your subtitles match your audio. This format is widely accepted by video hosting sites such as Vimeo or YouTube.

Project management

If you’re dealing with a large subtitle translation project, you’ll need a software that can support your workflow. With Lokalise, you can create chained tasks, assign them to translators, and automate rules. By speeding up repetitive tasks and streamlining your localization efforts, you’ll get to market much faster.

Glossary and translation memory

Create and share a glossary (also known as a termbase) to ensure industry-specific terms are maintained throughout your subtitle translation project. You can also use the glossary across multiple projects and between multiple collaborators. 

Using translation memory will vastly help your translators too. They won’t need to repeatedly translate the same things, and can maintain consistency throughout the project.

🧠 Good to know
Lokalise can help you easily manage all types of translations, centralize your workflows, and automate parts of the process for greater efficiency.

Built-in translation providers

Just need to translate subtitles for a few videos, but don’t want to hire or outsource to a whole team? Choose from one of our translation providers, who also offer bilingual editing or proofreading options.

Quality assurance

Our quality assurance features make sure you don’t miss those pesky grammar and spelling mistakes, and you can automate everything for an even faster turnaround.

AI-powered subtitle translation

With Lokalise AI, you can significantly speed up your subtitle translation process and lower your cost. If you upload your Style Guide and Glossary, the machine translation accuracy will be very high. Still, it’s recommended to have a native speaker check the translated subtitles and verify they’re ok.

We invite you to try Lokalise for 14 days, completely free. You’ll get the chance to explore the platform and evaluate if it matches your subtitle translation project needs.

FAQs about subtitling translation