Best AI Tools for Translation and Localization

Pick a translation tool by what you're translating, not by which AI model sounds best. A marketing site, the buttons and menus in an app, a help center, a contract and a mobile release each need a different setup.

The short version:

• DeepL if you want strong machine translation and an API to call it from your own tools.
• Weglot if you want your website in other languages fast.
• Lokalise if your team ships app text all the time.
• Phrase if translation is already a company-wide job.
• Crowdin for developer-led or open-source projects with volunteer translators.
• Smartcat if you want AI plus a marketplace of human experts.
• Smartling if a large company needs translation tied into its CMS and quality checks.

This comparison comes from each vendor's pricing and documentation pages, read on September 27, 2026. No tool was tested for translation quality. Prices change, so open the linked page before you budget.

Translation is a loop, not one task

Translating one PDF is a single job. Keeping a website or app in six languages is a loop that never stops:

1. Notice new text that needs translating.
2. Translate it with AI, with past translations you've saved, or with a human.
3. Keep key terms consistent with a glossary.
4. Have someone review the risky parts where they'll actually appear.
5. Publish the translation back to the website, app, CMS, code repository or document system.
6. Track what changed, so the next update doesn't start from zero.

A one-off translator only handles step 2. The tools below differ in how much of the rest they cover. A tool that runs the whole loop is called a translation management system, or TMS.

Quick comparison

1. DeepL: best AI translation engine and API

Start with DeepL when the job is good machine translation, translating documents, or translating through an API from your own software. DeepL charges API use by the characters of text you send in, counted on requests that succeed. Spaces, tabs and line breaks count too, per DeepL's API billing page.

The API plans set how much you can spend. The same page says DeepL API Free includes up to 500,000 characters per month. DeepL API Growth includes 1 million characters and 10 hours of speech-to-text on monthly billing, or 12 million characters and 120 hours on yearly billing. Growth tops out at 50 million characters and 300 hours of speech-to-text a month, and past that you're talking to their enterprise team, per DeepL's billing documentation.

DeepL is worth it when you need:

• API translation inside a product or workflow.
• High-quality draft translations for docs, support, sales, and operations.
• Glossary-driven consistency before human review.
• A translation layer you can connect to another system.

DeepL translates. It doesn't manage the rest of the loop. Pair it with Lokalise, Phrase, Crowdin or your own code repository, so saved translations, screenshots, approvals and publishing have a home.

2. Weglot: best AI website translation tool

Weglot is the clearest pick if you want a marketing site or online store in several languages without building anything yourself. Its pricing page lists a free plan with 2,000 words and one translated language, a Starter plan at $17 per month or €15 per month for 10,000 words, and a Business plan at $32 per month or €29 per month for 50,000 words and three translated languages, on Weglot's pricing page.

Weglot's strength is speed. You launch translated pages, each language gets its own URL so search engines can find it, and then you go back and hand-edit the pages that matter. Higher tiers add larger word limits, more languages, import and export, custom languages and enterprise security, per Weglot pricing.

Use Weglot when you want:

• A translated website without much engineering work.
• Translated URLs and search settings for each language.
• A word-count pricing model you can predict.
• A fast launch for a small or mid-sized site.

Skip Weglot as your main system for the text inside an app, mobile releases, or translations that live in a code repository. A TMS handles those better.

3. Lokalise: best for product and software localization

Lokalise is built for teams translating apps, SaaS products, games and the other bits of text inside a product. Its pricing page lists Explorer at $149 per month, Growth at $379 per month and Advanced from $1,049 per month, all with annual billing, plus custom Enterprise pricing and a 14-day free trial, on Lokalise's pricing page.

Read past the headline price. The same page's plan table gives Explorer unlimited standard seats and hosted words, up to 5 projects, 10 languages, processed words from 60,000 a year and 240,000 Standard AI/MT translated words a year.

Growth adds unlimited projects, languages and Standard AI/MT words, 40,000 Pro AI translated words a year, glossary and translation memory, and processed words from 225,000 a year. Processed words are the limit to watch. Every plan can buy add-on bundles.

Choose Lokalise when your team needs:

• GitHub, CLI, API, webhook, or design-tool workflows.
• Screenshots and in-context review.
• Saved past translations (translation memory) and glossaries.
• Product managers, developers, translators, and reviewers working in one system.

It's the same pattern as any AI document workflow. Text goes into one system, AI does a first draft, people review the risky parts, and approved text goes back into the product.

4. Phrase: best for enterprise localization platforms

Phrase does more than translate. It bundles a TMS, tools for app text, machine translation, AI features, reporting, automated workflows, integrations and admin controls. Its pricing page lists a Team business plan with unlimited TMS seats, 20 Strings seats, every Phrase product, and $1,245 per month billed annually, with Business and Enterprise priced custom, on Phrase pricing.

Phrase also publishes the limits. The Team plan includes 1,200,000 Phrase Strings managed words, 2,500,000 TMS processed words per year, 12,000,000 Machine Translation Units per year, 25,000 AI units per year, and three Phrase Orchestrator workflows, per Phrase's pricing table.

Use Phrase once translation is already a company-wide job that touches product, marketing, support, documentation and outside vendors. It's too much for a founder translating a small website. It fits a company that wants permissions, saved translations, vendor management, quality checks and reporting in one place.

5. Crowdin: best for developers and community translation

Crowdin fits projects run by developers, translations done by a community of volunteers, open-source projects, and any team that wants integrations before it commits to a big enterprise TMS. Its pricing page centers on a plan calculator, hosted-word limits, and over 700 apps and integrations for syncing text and translations across tools, on Crowdin pricing.

Hosted words are easy to misread. Crowdin counts them as your original words times the number of languages. Upload 500 words to a project with 10 target languages and that counts as 5,000 hosted words, per Crowdin's pricing FAQ. Do that math before you compare Crowdin's price to a per-character API or a per-processed-word TMS plan.

Crowdin is a good fit when:

• Developers want translations to live alongside their code.
• Community translators or open-source contributors are involved.
• You need glossaries, saved translations, integrations, online editing and reports.
• You want to invite unlimited translators and proofreaders on paid plans, per Crowdin pricing.

6. Smartcat: best for AI plus human experts

Smartcat now sells itself around AI coworkers and content workflows. Its pricing page lists Adapt starting at $1,200 per year, Accelerate at $24,000 per year, Anticipate at $60,000 per year, and a custom Autonomous tier, on Smartcat pricing.

What sets Smartcat apart is the marketplace. Accelerate includes marketplace experts, with access to 500K+ experts listed on Smartcat's pricing page. That helps when AI can do the first draft but you still need a human translator, reviewer, copywriter or subject expert to sign off.

Use Smartcat when translation, adaptation, review, and vendor work all live in the same process. Skip it for a lightweight website widget or a small API translation layer.

7. Smartling: best enterprise TMS for CMS-heavy teams

Smartling fits large companies that publish through a CMS and need to check translation quality at scale. Its TMS page says Smartling connects to content software through pre-built integrations, custom APIs and its Global Delivery Network, with language quality checks and quality dashboards built in, on Smartling's translation management page.

Smartling makes the most sense once translation has to cover several parts of a business: marketing pages, support content, product docs, store listings and CMS publishing. It's not the easy option for a small site. It pays off when the volume and the need for control are big enough to justify the setup work.

Which setup fits your situation

A website

Use Weglot to translate the site, then hand-edit your busiest pages. Add a glossary for brand terms, product names and any phrase you never want translated word for word. Review the pages that bring in money or leads first, not every page equally.

A software product

Use Lokalise, Phrase or Crowdin. Connect your code repository, pull in the app's text, let saved translations and AI translation work together, require a reviewer on important screens, then send approved translations back into your release.

Support articles and documentation

Use DeepL or Phrase for drafts, and add a TMS if the docs change often. Start with your most-read help articles, onboarding steps, refund policies and troubleshooting pages.

An agency translating for clients

Use Smartcat when you want AI drafts and human experts in one place. Use Weglot for small client websites, and Lokalise or Crowdin for clients with apps.

A large company

Use Phrase or Smartling when translation spans teams, regions, vendors, compliance rules, reporting, and CMS or product integrations. At that size the AI model is rarely what decides it. Permissions, reusing past translations, automation and reporting do.

What to avoid

Don't publish AI translation of legal, medical, financial, HR or compliance content without a human review.

Don't translate a lone piece of app text without a screenshot or context. Short button labels are where word-for-word translation fails hardest. "Save" can mean store a file or rescue someone.

And don't choose a tool on per-word price alone if you also need saved translations, approvals, branch management or search settings for each language.

What to do next

Write down what you're translating and where it gets published. That one line usually points to one or two tools from the list at the top. Open their pricing pages, check the limits against your word count, and start a trial before you commit. If you're building the translation step into a bigger automation, the playbook below covers how to put AI drafts, checks and human review in the right order.

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• Enterprise Document Processing Tools: How to Choose