AivisSpeech
AI & Generative AI
Free speech synthesis software that produces emotionally expressive voices, usable for video narration, voice dramas and similar.
Free planAIJapanese UI
List of apps that support Japanese
79 apps
79 apps that APP NAVI confirmed from official sources to support Japanese. Last checked: 2026-11-05. Anything we could not confirm stays "Unverified"; we never guess. Prices and specs change, so check each app's official page before you use it.
assift(アシフト)
Daily Life & Utilities
A web service dedicated to building shift schedules: AI drafts a schedule from your conditions, and you share it by URL. Free for up to 10 staff.
Free planAIJapanese UI
AtCoder
Education & Learning
A competitive programming site that holds regular contests of several kinds such as ABC, ARC and AGC, with rankings and practice contests.
Japanese UI
AtCoder Problems
Web Services & Online Tools
A web app that helps AtCoder users solve problems and manage their progress, under the tagline 'Extend your AtCoder'.
Free planJapanese UIIndie
Biome
Programming & Dev Tools
A toolchain for web projects offering a formatter and linter, usable via CLI and LSP.
Japanese UI
Booking Package
WordPress (plugins & themes)
A booking plugin that lets you take reservations such as rooms, services and events directly on WordPress pages.
Free planJapanese UI
Celeste
Games & Entertainment
A precision platformer in which Madeline climbs Celeste mountain while confronting her inner struggles.
Japanese UI
ChatdollKit
AI & Generative AI
A Unity SDK for turning a 3D model into a voice-enabled chatbot. It supports several LLMs such as ChatGPT, Claude and Gemini and speech synthesis such as VOICEVOX and AivisSpeech.
Free planAIJapanese UIIndie
Clibor
Daily Life & Utilities
A free clipboard-history tool for Windows that keeps copied text and pastes saved phrases instantly.
Japanese UI
CloudSecure WP Security
WordPress (plugins & themes)
A Japan-made security plugin that protects the admin area and login URL from unauthorized access, with simple on/off feature toggles.
Free planJapanese UI
CMAN インターネットサービス
Web Services & Online Tools
A site for IT engineers and web creators with tools such as server monitoring, QR code generation, an .htaccess generator and image editing. Almost all services are described as free.
Japanese UI
CmdDeck
Mobile Apps
A command reference app for IT work on iOS, iPadOS and macOS. It lists 1,510 commands and 120 troubleshooting flows, works fully offline, supports 9 UI languages and is a one-time purchase.
Japanese UIIndie
COEIROINK
AI & Generative AI
A free speech synthesis app that reads text aloud in character voices. It is distributed for Windows, Mac and Linux, and lets users create their own voice with the MYCOEIROINK feature.
Japanese UI
Comfortable Admin Page
WordPress (plugins & themes)
Gathers hard-to-reach admin settings in one place so you can tailor a friendlier WordPress dashboard.
Free planJapanese UI
Cosense (Scrapbox)
Business & Operations
A tool for sharing and organizing knowledge by writing and linking pages. Free for personal or non-profit use; the Business plan is listed at JPY 1,100 per user per month.
Free planJapanese UI
CotEditor
Programming & Dev Tools
A lightweight plain-text editor for macOS with syntax highlighting and regex search, plus CJK-friendly features such as vertical text and encoding detection. It is free on the Mac App Store.
Free planJapanese UIIndie
Dify
AI & Generative AI
A platform for building agentic workflows, agents and knowledge pipelines on one canvas, deployable on cloud, in your VPC, or self-hosted.
Free planAIJapanese UI
Editor Bridge
WordPress (plugins & themes)
Extends the block editor's core blocks with extra styles and formats.
Free planJapanese UI
Fedibird
Social & Communication
A general-purpose Mastodon server in Japan run by admin noellabo, offering many original features. New registrations were suspended at the time of checking.
Japanese UIIndie
FireAlpaca
Image, Photo & Design
A free paint tool with brushes, layers, comic panel features and filters; a paid FireAlpaca SE is sold on Steam.
Free planJapanese UI
Flexible Table Block
WordPress (plugins & themes)
Adds cell merge/split and per-element styling to the table block in the block editor.
Free planJapanese UI
FormNest
WordPress (plugins & themes)
A form plugin built around Japanese contact-form conventions, with a confirm screen and postal-code address autofill.
Free planJapanese UI
Fukasawa
WordPress (plugins & themes)
A minimal masonry-style blog theme for photographers and collectors.
Free planJapanese UI
GROWI
Business & Operations
An open-source Markdown wiki for team knowledge sharing, with real-time co-editing, permissions and an AI agent.
AIJapanese UI
Gyazo
Web Services & Online Tools
A capture tool for screenshots and video that creates a shareable URL right away. It offers shortcut capture, OCR search, tags and collections.
Free planAIJapanese UI
Hayabusa(隼)
Security & Privacy
A Rust tool that builds fast forensic timelines and performs threat hunting on Windows event logs using Sigma rules, developed by Yamato Security.
Japanese UI
Kero Blaster
Games & Entertainment
A side-scrolling action game from the team behind Cave Story, in which a frog office worker fights monsters on a business trip.
Japanese UI
Leasy
Mobile Apps
A simple flashcard-style memorization app where you add your own words or phrases. It offers multiple-choice and typed questions, review of missed items and a random test, with data kept on the device.
Free planJapanese UI
Lightning
WordPress (plugins & themes)
A simple, easily customizable Bootstrap-based theme that works well with custom post types and taxonomies.
Free planJapanese UI
Lovecraft
WordPress (plugins & themes)
A two-column blogger theme with a full-width header image and custom accent color support.
Free planJapanese UI
Mery
Daily Life & Utilities
A lightweight text editor for Windows that can be extended with macros and color themes.
Japanese UIIndie
Mindustry
Games & Entertainment
A sandbox tower-defense game where you build factories to process materials and defend your base against enemy waves, with multiplayer servers.
Free planJapanese UI
Misskey
Social & Communication
Free open-source software for building social networking services, with ActivityPub support for Fediverse federation. It has a responsive web UI and PWA support.
Free planAIJapanese UIIndie
Online Lesson Booking
WordPress (plugins & themes)
A scheduler and booking form for one-on-one online lessons, with email notifications for bookings and cancellations.
Free planJapanese UI
Organic Maps
Mobile Apps
An offline maps and navigation app built on OpenStreetMap data. The official site says it has no ads or tracking and is free.
Free planJapanese UI
Papers, Please
Games & Entertainment
A game in which you play a border inspector in the communist state of Arstotzka, deciding who may enter by checking documents.
Japanese UI
Pochipp
WordPress (plugins & themes)
Search products on Amazon and Rakuten and manage affiliate links from within WordPress.
Free planJapanese UI
PrivacyPhoto
Image, Photo & Design
A browser-based tool for inspecting and removing GPS and other Exif data from photos; the page states photos are not sent to any server.
Japanese UI
Rams
WordPress (plugins & themes)
A clean, minimalist responsive theme for bloggers.
Free planJapanese UI
sd-scripts
AI & Generative AI
A collection of training, generation and utility scripts for Stable Diffusion and other image generation models, covering LoRA training and fine-tuning. Japanese versions of the README and docs are provided.
Free planAIJapanese UIIndie
SHAREVOX
AI & Generative AI
A free text-to-speech app that uses deep-learning speech synthesis. The official site says users can adjust intonation and speed in detail and create a voice from their own recording.
Free planAIJapanese UI
Simple Days
WordPress (plugins & themes)
A free responsive blog theme designed mobile-first.
Free planJapanese UI
Smalruby
Education & Learning
A programming learning environment, modelled on Scratch, where children build programs and robots with Ruby. It is developed by the NPO Ruby Programming Shounendan.
Japanese UI
Stardew Valley
Games & Entertainment
A farming life sim where you inherit your grandfather's farm. You grow crops, raise animals, fish, befriend townsfolk and explore caves.
Japanese UI
Style-Bert-VITS2
AI & Generative AI
Text-to-speech software based on Bert-VITS2 that generates emotional speech, with controllable emotion and speaking styles.
AIJapanese UI
Subway Tooter
Mobile Apps
A Mastodon client for Android phones and tablets. It features simultaneous multiple accounts, rearrangeable multi-column views and extensive filters.
Japanese UI
Suzaku(朱雀)
Security & Privacy
A Rust threat-hunting and fast forensics timeline generator for cloud logs such as AWS CloudTrail, Azure/Entra ID/M365 and Google Workspace, with native Sigma support.
Japanese UI
Tablacus Explorer
Daily Life & Utilities
A tabbed, Explorer-compatible file manager for Windows that is extensible with add-ons and runs portably without installation.
Japanese UI
Takajo(鷹匠)
Security & Privacy
A fast forensics analyzer for Hayabusa results, written in Nim. It can extract indicators, build timelines and process trees, and generate HTML reports.
Japanese UI
Taski
Business & Operations
A team issue tracker that shows the same issues as list, board, Gantt and calendar views, with import from Redmine and Trello.
Free planAIJapanese UI
Tatoeba
Education & Learning
A collaborative multilingual sentence collection with translations, useful for finding example sentences when learning languages; it has a Japanese interface.
Free planJapanese UI
Tera Term
Programming & Dev Tools
An open-source terminal emulator with an SSH module (TTSSH). Japanese manuals and language files for localizing menus are provided.
Japanese UI
TheDesk
Social & Communication
A desktop client for Mastodon (and Misskey) with a multi-column timeline layout. The official site says v25 onward is a modified version of Fedistar.
Japanese UIIndie
tide736.net
Daily Life & Utilities
A site offering tide tables for 736 ports along the Japanese coast, plus a tide calendar and API. It states it does not replace the official tide tables of the Japan Coast Guard.
Japanese UIIndie
Timberborn
Games & Entertainment
A city-building sandbox starring beavers, set in a world struck by drought and toxic waste, with vertical architecture and water physics.
Japanese UI
Tux Paint
Education & Learning
A free drawing program for children aged 3 to 12. The official site states it has no ads, is open source under the GPL and is built by a worldwide volunteer team.
Free planJapanese UIIndie
UGTOP
Web Services & Online Tools
A Japanese-language site that publishes tools such as the "Kakunin-kun" environment checker. Its copyright notice reads "1997- ugtop".
Japanese UI
UNDERTALE
Games & Entertainment
An RPG introduced on its official site as one where you do not have to destroy anyone.
Japanese UI
UTAU
Video, Audio & Music
A singing voice synthesis tool. The official download page distributes a Windows installer and publishes a version history.
Japanese UI
Vampire Survivors
Games & Entertainment
A gothic-horror roguelite survival game where you fight hordes of monsters until dawn.
Japanese UI
Vivliostyle
Web Services & Online Tools
An open-source CSS typesetting project for digital and web publishing. The site is available in Japanese and English, and a CLI is provided.
Japanese UI
VOICEVOX
Video, Audio & Music
Free text-to-speech and singing voice synthesis software; the page states it is free for commercial and non-commercial use subject to each character's terms.
Free planJapanese UI
waifu2x
Image, Photo & Design
A web service that upscales and denoises anime-style art and photos using deep convolutional neural networks, with a 20-language interface.
AIJapanese UIIndie
WOLF RPGエディター(ウディタ)
Games & Entertainment
A free RPG-making tool driven by Japanese-language commands. The official site says games made with it may be freely distributed, sold or submitted to contests.
Free planJapanese UIIndie
Word Balloon
WordPress (plugins & themes)
Adds speech balloons to posts. Supports both the block and classic editors and ships with a Japanese translation.
Free planJapanese UI
XO Security
WordPress (plugins & themes)
Strengthens login security with a login log, attempt limits, captcha, login URL change and two-factor options.
Free planJapanese UI
Yes/No Chart
WordPress (plugins & themes)
Lets you create a yes/no question flow (a yes/no chart) on a WordPress site.
Free planJapanese UI
Zenn
Web Services & Online Tools
A knowledge-sharing community for engineers where users can publish articles and books. Its tagline is 'Write for yourself.'
Japanese UI
アサリツールズ (Asari Tools)
Web Services & Online Tools
A free collection of web tools for streamlining web work, including text formatting, image conversion and SEO analysis, run by Studio Asari LLC in Nagoya.
Free planJapanese UI
サクラエディタ (Sakura Editor)
Programming & Dev Tools
A free text editor for Windows with a Japanese-language focus. Its source code is published on GitHub.
Free planJapanese UI
ティラノスクリプト
Games & Entertainment
A free tool for making visual novel games. Games can be published for PC, smartphones and browsers, and the official site says commercial use has no restrictions.
Free planJapanese UI
ドットインストール (dotinstall)
Education & Learning
A programming learning service built on videos of three minutes or less. Its top page lists 578 lessons and 8,635 videos, and it is run by dotinstall Inc. in Meguro, Tokyo.
Free planJapanese UI
ドリトル (Dolittle)
Education & Learning
A programming language designed for education. The official site says it is used in textbooks and supplementary materials for junior and senior high schools and in classes from elementary school to university.
Japanese UI
なでしこ3 (Nadesiko3)
Education & Learning
An open-source programming language in which programs are written in Japanese, aimed at automation and learning to program. A web version and a PC (Go) version are available.
Free planJapanese UI
ビスケット (Viscuit)
Education & Learning
A visual programming language for kids built around a single concept, the glasses, to make pictures move and react.
Japanese UI
ポイピク (Poipiku)
Image, Photo & Design
A Japanese web service for posting and managing illustrations. It supports uploading up to 200 images at once and anonymous emoji reactions.
Japanese UI
ゆっくりMovieMaker4
Video, Audio & Music
A video editor for yukkuri-style commentary videos, offering video export, template features and support for many speech-synthesis tools and services.
Free planJapanese UIIndie
ゆめにっき (Yume Nikki)
Games & Entertainment
A walking-style adventure set in a dreamlike world with no set story or objectives.
Japanese UI
青空文庫
Web Services & Online Tools
An online digital library in Japanese. Works can be browsed by author and title, and usage rules are explained on the site.
Japanese UI