Writing tools
Adjust the reading surface, manage technical vocabulary, and choose how corrections work.
Text size
The status bar carries a text-size slider on its own row, just above Local, Export, and the word count. Drag it, use the − and + buttons beside it, or press Ctrl+= and Ctrl+- from anywhere in Paper; Ctrl+0 goes back to 100%. The range is 50% to 250%.
This changes the real type, not a zoom of the picture: the text redraws at the new size, the lines re-wrap, and the column of text widens or narrows with them. Nothing about the document on disk changes — text size is a reading preference for this device.
Click the percentage to choose which panels it applies to. The small window that opens has a checkbox for All panels together and one each for the Manuscript, the Left sidebar, and the Right margin — tick any one, any combination, or all three. By default the slider resizes the manuscript only, so the sidebar and margin keep their size while you make your text bigger. Each panel remembers its own size, and both the sizes and your choice of panels come back the next time you open Flux. At least one panel always stays ticked.
Local corrections
Paper fixes clear typing slips when you finish a word, using a local Harper worker. This first layer sends no manuscript text to a service. It leaves code, math, citations, links, tables and technical identifiers alone.
Turn local checking on or off with Local in the status bar or in Settings → Corrections.
A correction briefly pulses blue. Click the word to inspect it, undo it or add it to the dictionary. Ctrl+Z also undoes a correction batch. Undoing teaches the project to leave that correction alone.
Dictionaries and aliases
Select a word and open Word tools in the floating toolbar, or press Shift+Alt+W. Add it to the Project dictionary for this project, or Personal for all projects on this device. Shift+Alt+D toggles project recognition; Alt+D toggles personal recognition.
An alias expands a short form when you finish typing it. For example, igf can expand to iGluSnFR4f. Choose its scope in Word tools. Project aliases take precedence over personal ones; Ctrl+Z restores the typed form. Remove aliases through Word tools or the recent expansion’s menu.
Dictionaries help nearby misspellings resolve to a known technical term. They do not make every similar scientific name equivalent: recognizing SLAP2 does not turn SLAP3 into it.
Optional sentence judgment
Sentence judgment is a separate, optional layer that considers completed sentences to resolve uncertain spellings. It proposes individual word corrections, not sentence rewrites. Flux checks the suggestion again and discards it if you have changed the source text.
| Underline | Meaning |
|---|---|
| Red | The local checker flagged an unresolved word. |
| Blue, fading | A correction was applied. |
| Orange | Sentence judgment kept the word. Click to inspect the decision. |
Opening an existing document adds flags without correcting old text or sending it for sentence judgment. Editing a flagged sentence brings it into the normal checking workflow.
Choose a provider explicitly: Flux managed runs a downloaded local model; an existing Ollama installation is another local option; the optional cloud provider has its own key and disclosure. A local failure never enables cloud processing automatically.
Model setup, correction strength and learned preferences
Correction strength. Settings offers three levels. Standard is the default: one typing edit for short words and two otherwise. Aggressive can explore three edits for words of nine or more letters. Really aggressive explores every bounded candidate, allows three edits from seven letters and four from ten, and is intended for testing. All three keep the same safeguards: no sentence rewrites, and respect for syntax, scientific word forms, your dictionaries, the surrounding context and the exact source text. Wider levels can be slower, and they still leave a word alone when a safeguard fails.
Flux managed model. This is the default provider. Install the 2.33 GB Qwen3 4B Instruct 2507 model explicitly in Settings. The download resumes after an interruption, is SHA-256 verified under FluxConfig/Models/corrections/, and can be unloaded or removed there. Flux runs the model through its own pinned llama-server helper, which only this computer can reach and which requires authentication, and never starts it from the Home screen. Apple Silicon packages run the model fully on Metal; Linux packages use the pinned Vulkan backend when a GPU is available. Settings names the active acceleration path. “Ready” means the model has returned a valid test answer, not merely that its process has started. Use Update local model if Settings offers a newer verified version.
Ollama. An existing Ollama installation can be selected as an advanced local provider. Flux loads the selected Ollama model ahead of use, keeps it loaded for 15 minutes, and fixes its context at 2,048 tokens so a small correction request cannot allocate the model’s much larger default context. Loading may take longer in the background, but each correction must still arrive within the editor’s short window; a late result never changes the manuscript.
Cloud provider. GPT-5.6 Luna is separately opt-in. Its API key is encrypted by the operating system, requests use store: false, and Settings discloses what is sent and shows the session cost estimate. A local failure never switches to the cloud.
What the judgment learns from. Personal guidance, project guidance, dialect, explicit terms, aliases and learned “leave alone” decisions all inform it. Reset correction learning in the same Settings section clears automatic lessons without deleting dictionaries or aliases; individual lessons can also be removed from the visible list. Quoted material, code, math, citations, links, tables, front matter and technical identifiers remain protected in both layers.
Vim, and how the caret feels
For keyboard fans, Ctrl+K → Enable Vim mode turns on modal editing, with two flavors: plain Vim, or flux-ViM — Vim plus Flux’s opt-in refinements (the first: jj in insert mode is Escape). If you do not use Vim, leave it off.
Separately, Settings → Paper offers Caret motion: chase (the default — the caret pursues your typing with a lively, immediate feel) or smooth (a fixed soft glide).