# What Is a .stringsdict File? iOS Plurals and Width Variants > A .stringsdict is the XML plist that holds iOS plural forms and width-adaptive strings next to your .strings file. What is inside it, and how to edit it safely. Source: https://stringlane.app/docs/what-is-a-stringsdict-file Last updated: 2026-08-19 `.stringsdict` is the file extension for an iOS **strings dictionary**: an XML property list that holds the string variants `Localizable.strings` cannot express. It sits beside the `.strings` file it belongs to, in the same `.lproj` folder, and carries two things — **plural forms**, and **width-adaptive strings** that change with the space available on screen. ## What a .stringsdict looks like The file is a plist whose root dictionary is keyed by translation key. Each key maps to a dictionary holding a format key and one sub-dictionary per format variable: ```xml files_selected NSStringLocalizedFormatKey %#@count@ selected count NSStringFormatSpecTypeKey NSStringPluralRuleType NSStringFormatValueTypeKey d one %d file other %d files ``` Four parts do the work: - **`NSStringLocalizedFormatKey`** is the sentence, with `%#@count@` standing in for the variable. Anything around it is literal text that ships as-is. - **`count`** is the variable's own name — it is not a keyword. The key in the dictionary has to match the name inside `%#@…@`, and you can call it whatever you like. - **`NSStringFormatSpecTypeKey`** is the **rule type**: what the forms below are keyed by. - **`NSStringFormatValueTypeKey`** is the printf conversion for the value (`d`, `lld`, `@`, `f`, …). Note that the forms use printf specifiers — `%d`, `%@` — not ICU's `#`. A `.stringsdict` is not ICU MessageFormat; it is Apple's own structure for the same problem. If you also ship Flutter or i18next, see [What Is ICU MessageFormat?](/docs/icu-messageformat-explained) for the contrast. ## The two rule types **`NSStringPluralRuleType`** is the ordinary one. Its forms are CLDR plural categories — `zero`, `one`, `two`, `few`, `many`, `other` — and which of them a language actually requires varies: English needs two, Polish and Ukrainian need `few` and `many` as well, Arabic uses all six. **`NSStringVariableWidthRuleType`** is the one most people have never used. Introduced in iOS 9, its forms are keyed by device **M-width** — approximately how many capital `M` glyphs fit in the space available — rather than by grammatical number: ```xml bluetooth_label NSStringLocalizedFormatKey %#@width@ width NSStringFormatSpecTypeKey NSStringVariableWidthRuleType 20 BT 40 Bluetooth ``` That label renders `BT` on a narrow screen and `Bluetooth` where there is room. Width entries carry no `NSStringFormatValueTypeKey` — there is no number to format. The distinction matters more than it looks. Treat a width entry as a plural and the tooling starts demanding CLDR categories it will never have: a project that can never reach 100% translated, and bulk translation that writes `one` and `other` into an entry iOS selects by width. Xcode cannot read the result. ## Entries with more than one variable A single entry may declare several format variables, usually written positionally so translators can reorder them: ```xml NSStringLocalizedFormatKey %1$#@files@ and %2$#@folders@ ``` Each variable then gets its own sub-dictionary with its own rule type and its own forms. This is valid and it works, but it is considerably harder for tooling to model than the single-variable case — see below. ## How StringLane works with .stringsdict StringLane loads a `.stringsdict` as the **companion of its `.strings` file**: same `.lproj` directory, same filename, different extension. `en.lproj/Localizable.strings` pairs with `en.lproj/Localizable.stringsdict`. An absent companion is normal — not every locale ships plurals. A `.lproj` folder holding a `.stringsdict` with no matching `.strings` is not picked up, because the pairing is derived from the `.strings` entry. Plural keys appear in the detail pane as one panel per locale with a row per form, each with its own validation rail and character-width bar. To turn an existing `.strings` key into a plural, hover a non-empty cell and click its `{}` **Format helper** button, switch to the **Plural reference** tab, and use **Convert this key to plural** (it appears only for keys that are not plurals already). ![The itemsSelected plural key in the detail pane: English, German, French and Japanese panels each with one and other rows, French offering a CLDR-required many chip, and Japanese showing both forms as MISSING](/docs-screenshots/stringsdict-plural-forms.webp) ### Editing width entries A width-adaptive key announces itself. The panel shows a badge reading *Selected by available width (NSStringVariableWidthRuleType), not by grammatical number*, the form count reads "2 widths" rather than "2 forms", and the row labels are the numbers themselves. ![The bluetoothLabel key with a WIDTH-ADAPTIVE badge on every locale panel, rows labelled 20 M and 40 M holding BT and Bluetooth in English and French, MISSING in German and Japanese, and an Add width input under each panel](/docs-screenshots/stringsdict-width-adaptive.webp) The CLDR chip row is replaced by an **Add width:** input. A width has to be a plain positive integer — `20`, not `020`, `+20`, or `2,0` — because `020` and `20` are distinct plist keys but the same number, and accepting both would let you create two rows iOS reads as one threshold. Reserved names (`NSStringFormatSpecTypeKey`, `NSStringFormatValueTypeKey`) are rejected too: they live in the same dictionary as the forms and would collide with the entry's own declarations. A width that is already in your file is displayed and preserved whatever it looks like — the rule gates what StringLane will *write*, not what it will read. New widths are inserted in numeric order rather than appended, so adding `30` to an entry that has `20` and `40` puts it between them. If the existing widths are not in ascending order, that is your arrangement, and the new one appends instead of imposing a sort on a file you did not ask to be reordered. AI translation is width-aware: the model is told the number is an M-width and not a quantity, told not to invent plural categories, and told that a form's translation must be no longer than the source for that same width — otherwise the string stops fitting the screen the entry exists to serve. Validation likewise raises no "missing plural category" issue against a width entry. ### Multi-variable entries are read-only An entry declaring more than one format variable is shown but not editable. It is marked **UNSUPPORTED** in the key sidebar, and its detail pane reads *StringLane can't edit entries with more than one format variable. Edit this one in Xcode.* — with the format string and every variable's forms rendered below it, so you can still read what is there. ![The read-only panel for filesAndFolders: the message that StringLane can](/docs-screenshots/stringsdict-unsupported-entry.webp) It is preserved exactly on save. The entry is transcribed whole when the file loads and written back from that record, so editing other keys in the same file never disturbs it. ### What round-trips unchanged Saving a `.stringsdict` rebuilds the file, so anything StringLane does not record would be lost. It records, per entry: - the format variable's **name** — your `%#@itemCount@` does not come back as `%#@count@` - the **literal text** around the variable, so `%#@count@ selected` keeps its trailing word - the **value type**, including its *absence* — an entry that declared none does not acquire one - the **rule type**, so a width entry is never rewritten as a plural - the **order of keys** inside each sub-dictionary, and the **order of entries** in the file One rule overrides the recorded value: a width rule is never emitted above CLDR quantity forms. That pairing is not a valid entry in any circumstance — Xcode cannot read it — so preserving the declaration would mean writing you a broken file rather than preserving your file. ### When the file gets written The companion is written only when the locale actually has plural or multi-variable content. Removing the last plural key is the exception that has to reach disk, or the key would return on the next load. Before emptying a `.stringsdict`, StringLane re-reads it and re-parses it, and replaces it only if it parses to content StringLane recognises. An empty in-memory map is also what an unreadable plist produces, and a file whose only fault is that we do not understand it should not be destroyed on that signal. ## .stringsdict vs .xcstrings String Catalogs ([`.xcstrings`](/docs/what-is-xcstrings), Xcode 15+) fold all of this into one JSON file per string table, with plural and device variations expressed inline and a translation state per string. There is no companion file to keep in sync. If you are starting a new project, use String Catalogs. If you are on `.strings` and `.stringsdict`, there is no urgency — Xcode still builds them, and plenty of shipping apps stay there. StringLane edits both, and handles workspaces that mix the two mid-migration. ## Next steps - **[iOS strings editor](/strings-editor)**: what StringLane validates in a `.strings` project. - **[How to Use the Format Editor](/docs/use-format-editor)**: format-specific editing for iOS, Android, and i18next. - **[Working with ICU Plurals and Select Forms](/docs/working-with-icu-plurals)**: the ICU side, for ARB and i18next projects. - **[How to Read Validation Badges](/docs/read-validation-badges)**: what each badge means. ## Frequently asked questions ### What is a .stringsdict file for? A .strings file holds one string per key, so it cannot express "1 file" versus "3 files". The companion .stringsdict is an XML property list that stores the variants: one sub-dictionary per key, holding a form for each plural category the language needs. iOS picks the right one at runtime. ### What do the numbers 20 and 40 mean in a .stringsdict? They are device M-widths, used by entries whose rule type is NSStringVariableWidthRuleType. The number is roughly how many capital M glyphs fit in the space available, so one label can render BT on a narrow screen and Bluetooth where there is room. They are not quantities, and CLDR plural rules do not apply to them. ### Do I still need a .stringsdict if I use String Catalogs? No. A .xcstrings catalog expresses plural and device variations inline, so there is no separate file. .stringsdict is only needed for projects still on .strings, which Xcode continues to build. ### Can I put plurals directly in Localizable.strings instead? No. The .strings format is flat key-value pairs with no way to express variants, which is exactly why .stringsdict exists. The two files work as a pair: the key lives in .strings and its plural forms live in the .stringsdict beside it.