Write it like a map, read it like a script
Branching dialogue gets lost in a text file. Here every line is a card and every choice is an arrow, so you see at a glance where a conversation splits, where it meets again and where it ends. Click a card to edit it on the left. Pick where a line continues, or turn on player choices and give each one a target. Choosing New card in a target list makes the next card for you.
Choices, conditions and variables
A choice can carry a condition such as gold >= 10 or met_king and not angry, so it only shows when it makes sense. A line can change variables when it shows, for example gold -= 10; has_key = true. A Condition card sends the conversation one way or the other without asking the player. Variables you use show up in the Variables list, where you set their start values.
Play it right away
The player box under the map runs the conversation from the start card, with the current card highlighted on the map and the variables shown underneath. The checker lists dead ends, cards nothing leads to, missing targets, empty lines and conditions that do not parse. Click an issue to jump to the card.
Export to your engine
Ren'Py gets a .rpy file with characters, defaults, labels and menus. Ink gets an .ink story with knots, conditional choices and variables. Yarn Spinner gets a .yarn file with nodes and declarations. Godot gets the conversation as JSON plus a small DialogueRunner.gd that walks it and emits signals for lines, choices and the end. Unity gets the JSON plus DialogueRunner.cs. All + CSV adds a script sheet with every line and choice, ready for translators and voice actors.
Your writing stays yours
Everything runs in your browser and is saved in it. Save a project file to keep a copy or move to another computer.