An .xcstrings editor that keeps translation state honest
StringLane opens Localizable.xcstrings outside Xcode, shows every language side by side, and updates each string's state when you edit so the catalog does not drift out of sync with reality.
$49 once · No email · Full app for 14 days
The format
What StringLane opens
A String Catalog is one JSON file per string table holding every locale, plus a translation state for each string in each language. That state is the feature, and it is also the thing hand-editing the JSON gets wrong: change a value in a text editor and the surrounding state does not move, so Xcode's view of what still needs translating quietly stops being true.
- File layout
- One
Localizable.xcstringsper string table, all locales inside it - Placeholders
%@,%d,%lld, and positional forms such as%2$@- Plurals
- Apple variations, stored inline in the catalog
- Per-string state
new,needs_review,translated- Detected by
- Any
.xcstringsfile, including several across sibling targets - Project chip
XCS
Verification
What gets flagged in a String Catalog
Validation runs when the catalog loads and again after every edit. These are the checks that apply to `.xcstrings`.
Missing or empty per language
The string exists in your source language and is absent or blank in another. In a catalog with thirty languages this is the number you cannot hold in your head, which is the entire reason for the side-by-side view.
Format specifier mismatch
Apple specifiers are positional, so they are compared by count rather than by name. If the source has %@ and %lld and the German translation came back with one specifier, that is an error, and it is the class of mistake bulk AI translation produces most often.
Plural coverage against CLDR
Each language is checked against the plural categories it actually requires. Ukrainian needs one, few, many and other. English needs two. Supply only the English pair and the missing categories are flagged, which you can verify without reading the language.
Same as source, and guarded words
A value identical to the source language usually means it was copied and never translated. Terms you mark as guarded, such as your app name, are flagged when a locale changes them instead.
What it will not do. ICU MessageFormat validation does not apply here, and StringLane does not pretend otherwise. String Catalogs express plurals as Apple variations, not as ICU strings, so the ICU checks you would get on an ARB or i18next project are switched off for this format. Plural coverage is still checked, through CLDR.
Your files
The catalog stays canonical
StringLane writes to the same `.xcstrings` file Xcode reads. There is no export step and no second copy of your strings.
- Translation state is updated for you: a value you fill becomes
translated, one you clear reverts tonew. - Strings marked
shouldTranslate: falseare left alone, including their state. - Adding a language merges into the existing file rather than creating a second one.
- The JSON shape is preserved, so the file Xcode opens afterwards is the file it expects.
Your toolchain
Where it sits in an Xcode project
Xcode still owns extraction. It pulls string literals out of your code into the catalog at build time, exactly as before, and StringLane never touches your .xcodeproj or .xcworkspace. What it changes is the editing surface: instead of one language at a time in the Xcode inspector, every language is a column.
This is also why StringLane runs on Windows and Linux. The catalog is JSON, not a Mac-only bundle, so a cross-platform team can work on the same iOS strings without an Apple machine each.
FAQ
Xcode String Catalog questions
Do I still need Xcode?
What happens to translation state when I edit a value?
translated for that language, and clearing a value returns it to new. This is the main reason to use an editor that understands the format rather than opening the JSON in a text editor, where the state silently stays wrong.Does it touch strings marked shouldTranslate: false?
My project is mid-migration and still has .lproj folders. Does that work?
.lproj cluster and every .xcstrings file, and loads them as one project with keys namespaced by their origin folder. Saves go back to each origin in its own native format, so a half-migrated project keeps working.Can I add a new language?
Price
One purchase, no subscription
$49once
Early-adopter price. Full price after launch is $79.
- All five formats, not just this one
- Live validation while you edit
- AI fill with your own API key, or a local model
- macOS, Windows and Linux
- Updates within the major version
The comparison worth making is against a cloud TMS seat rather than against another editor. Lokalise lists $144 a month at entry and $999 a month on its Advanced plan, checked July 2026. That bill arrives every month. This one does not.
Docs
Read before you download
What is the .xcstrings format?
String Catalogs explained, including the per-string state model.
Opening an Xcode project
How multi-target workspaces and mixed-format projects load.
Reading validation badges
What each badge means and how to clear it.
Adding a language
Presets, and what happens to the catalog on save.
If your project has not migrated to String Catalogs, or has targets that never will, the `.strings` page covers `.lproj` folders and companion `.stringsdict` plural files.
.strings and .stringsdict editor