Construction planning

Open Planner Studio

Open-source construction planning with Gantt charts, critical path, resources and levelling, baselines and progress — and native IFC 4.3 as the file format. One task grid for your whole schedule: next to the Gantt and as a full table view, edited like a spreadsheet. Also opens MS Project (.mpp) files natively. On your desktop and straight in the browser.

Download v2026.9.0 Open in your browser View source
Open Planner Studio — Gantt-planning met WBS-structuur, relatiepijlen en voortgangsbalken, drie projecten tegelijk open en het eigenschappenpaneel met CPM-resultaat rechts
Open Planner Studio — de volledige tabelweergave met WBS, duur, geplande start en einde, taaktype, kritiek pad, totale speling en voortgang naast elkaar, met drie projecten open en het eigenschappenpaneel rechts
Open Planner Studio — Gantt met werkonderbrekingen als losse blokken met verbindingslijn, zoals gelezen uit een MS Project (.mpp)-bestand, met kritiek pad en eigenschappenpaneel
Open Planner Studio — resource-bibliotheek die als bron boven meerdere projecten staat, met arbeid, materieel en onderaannemers
Open Planner Studio — bezettingsoverzicht van de resource-bibliotheek over meerdere geopende projecten, met dubbelgeboekte dagen gemarkeerd en een histogram per resource
Open Planner Studio — resource-histogram onder de Gantt, met overallocatie en nivellering
Open Planner Studio — Rapport-tab met papierformaat, lettergrootte en afdrukvoorbeeld van de Gantt
Open Planner Studio — ingebouwde handleiding met quick-start en praktijkgidsen, waaronder het koppelen van een AI-assistent

One table for your whole schedule — and you edit it like a spreadsheet

The task list beside the Gantt and the full Table view are now the same table: the same columns, the same shortcuts, the same way of editing — wherever you work. It stays fluid at thousands of tasks, you move from cell to cell with the keyboard, and you paste whole blocks in from your spreadsheet in one go. Dependencies are now edited right in the cell; the separate Relations tab had become redundant and has been retired.

  • One table, two places — the same columns, shortcuts and edits beside the Gantt and in the Table view. Your column choice, widths and order are remembered per place.
  • Paste from your spreadsheet — several cells at once, applied in full or not at all. Values stay values instead of flattening to text, and read-only cells are skipped.
  • Dependencies in the cell — edit relations and jump to the linked task without leaving the table. The separate Relations tab has been retired as a result.
  • Days and hours — you choose per task whether its duration counts in days or in hours. An hour task consumes real working minutes on its own calendar, even when that calendar has a break in it.
  • Also new: your own task types, reports on A2 with a baseline overlay and status line, automatic saving back to your own file, and an interface that can follow the system theme.

We are looking for testers: work planners, schedulers, project leads and BIM coordinators. Try Open Planner Studio right in your browser and tell us what you think — your feedback helps shape where it goes.

Try the live demo → Join as a tester

Download v2026.9.0

Windows
7.3 MB
Download .exe
macOS (universal)
15.4 MB
Download .dmg
Linux (deb)
8.3 MB
Download .deb
Linux (rpm)
8.3 MB
Download .rpm
Linux (AppImage)
82.2 MB
Download AppImage
Linux (snap)
7.5 MB
Download .snap

Rather not install anything? Open Planner Studio also runs fully in your browser — including opening and saving files.

Features

AI assistant via MCP

An MCP server is built into the app, so an AI client such as Claude Code can read and edit your schedule directly. Switch it on in the AI tab, with a pause button, read-only mode and automatic backups.

Gantt charts

Interactive HTML5 Canvas Gantt with drag and drop, zoom and timeline navigation. Drag a whole selection vertically, collapse non-working days out of the timeline and select with Ctrl+click. Week numbers in the header.

Critical path (CPM)

Automatic critical path calculation with float, near-critical work, multiple critical paths and deadline analysis. A "dates as recorded" view shows a file exactly as it recorded its own dates, when those differ from recalculation.

WBS & table view

Hierarchical task structure with collapsible chapters. Beside the Gantt and in the full Table view you work in the same table: cell to cell with the keyboard, blocks pasted in from your spreadsheet, dependencies in the cell, columns you choose and pin, rows you drag. It stays fluid at thousands of tasks too.

Your own task types

Alongside the built-in types you can define your own task types. They are reusable on your installation, and their name and identity travel with the project — so what a task is stays readable after an IFC exchange or on another machine.

Automatic saving

Once your project has a file the app is allowed to write to, you can have it written back periodically — with no dialog. It deliberately stays separate from crash recovery: a document that has never been saved is never quietly overwritten, and the recovery snapshot keeps running alongside it.

Native IFC 4.3

Your schedule is an IFC file (buildingSMART standard). With a built-in IFC code editor to generate and apply.

Resources & levelling

Labour, equipment and subcontractors with a histogram and automatic levelling of overallocation. Move assignments while keeping units and curve.

Resource libraries

Share one resource pool across several projects. The library is the source, the project shows what it actually uses, and deviations are flagged so you can resolve them. The occupancy overview adds up every open project — as a table and as a histogram — and marks the days where the committed load exceeds the available capacity.

Baselines & progress

Capture multiple baselines and record progress with a status date, actual start and a cleaned-up progress line.

Calendars & hourly planning

Construction-specific calendars: public holidays, building recess, frost delay, inspection moments and phasing, plus a configurable break in the daily pattern. Per task you choose whether the duration counts in days or in hours; an hour task consumes real working minutes on its own calendar instead of being quietly converted to whole days.

Desktop and browser

Runs natively on Windows, macOS and Linux, but also fully in the browser — including open, save, auto-save and crash recovery.

Exchange

Import and export IFC, CSV, MS Project (.xml) and Primavera P6 (.xml) — no intermediate steps or conversion tools.

MS Project (.mpp) import

Opens .mpp files natively, with no Microsoft Project or converter involved — date-faithful to the minute across a 216-file test corpus. Split tasks, resource leveling, timephased assignments and manually scheduled tasks are read and shown as interrupted bars in the Gantt, print preview and PDF export; nothing from the source file is lost, even after you edit it.

4D BIM-ready

Your schedule is an open IFC 4.3 file. BIM software can lay it directly alongside your building model for 4D analysis of the construction sequence, with no conversion needed.

Reporting & printing

Live print preview in the ribbon and export to a real high-resolution PDF (±220 DPI). Paper up to A2, a baseline overlay, a status or progress line, bars coloured by task, category or resource, and non-working days you can compress. Configurable font size, a header that repeats on every page and a timeline that may span several pages. Your settings are remembered.

Manual inside the app

Press F1 for an offline manual, available in all fourteen languages: quick start, fifteen practical guides — including resource libraries and connecting an AI assistant — and sixteen reference pages, plus eight sample projects to practise on.

Shortcuts & context menus

Full overview via Ctrl+/ and rich right-click menus on the task row, Gantt bar, canvas and band header. Per-task notes with a tickable checklist.

14 languages

Nederlands, English, Français, Deutsch, Español, Italiano, Português, Polski, Türkçe, 中文, 日本語, 한국어 and RTL support for العربية and فارسی.

Ribbon toolbar

Familiar Office-style ribbon with tabs: Home, Planning, Resources, View, Settings, Table, IFC and Report — plus an AI tab once AI mode is on. Relation actions sit in the task groups themselves.

Technology

Tauri 2

Native desktop app with a Rust backend for Windows, macOS and Linux.

React 19 + TypeScript

Component-based UI with Zustand + Immer for state management.

HTML5 Canvas 2D

Gantt rendering. TailwindCSS 4 for styling, Vite 7 as the build.

Frequently asked questions

Can I open files from Microsoft Project or Primavera P6?

Yes. Open Planner Studio opens MS Project (.mpp) files natively — no Microsoft Project or external converter needed — and is date-faithful to the minute across a 216-file test corpus; split tasks, leveling delay, timephased assignments and manually scheduled tasks are read and shown. The app also imports and exports MS Project (.xml) and Primavera P6 (.xml) directly, with no intermediate step or conversion tool. IFC and CSV are supported as well.

Do I have to install anything?

No. The full application runs in the browser, including opening and saving files, auto-save and crash recovery. In Chromium browsers (Chrome, Edge, Brave, Opera, Vivaldi) Ctrl+S saves back over the same file, just like on the desktop; Firefox and Safari fall back to the file picker. If you do want to install, there are builds for Windows, macOS and Linux.

What file format is my schedule saved in?

IFC 4.3, the open buildingSMART standard. Your schedule *is* an IFC file — there is no proprietary, closed format. That keeps your data readable outside this application, and lets BIM software lay your schedule directly alongside an IFC building model for 4D analysis of the construction sequence.

What exactly can an AI assistant do with my schedule?

Since v2026.7.13 the app ships a built-in MCP server. An AI client such as Claude Code can read your schedule through it — project overview, tasks, critical path, resources, histogram, calendars and baselines — and edit it too. You switch the bridge on in the AI tab and stay in control: there is a pause button, a read-only mode, automatic backups and an activity panel listing every call the assistant made.

What does Open Planner Studio cost?

Nothing. The application is free and open source under the LGPL-3.0 licence. No subscription, no per-seat licence fees.

Which systems does it run on?

Windows (.exe), macOS (universal .dmg, both Intel and Apple Silicon) and Linux (.deb, .rpm, AppImage and snap). Plus fully in the browser.

Does it fit construction practice?

Yes. You set up construction-specific calendars with public holidays, building recess, frost delay, inspection moments and phasing, and you can plan down to hour level. The interface is available in fourteen languages.

Can I see which tasks drive the end date?

Yes. The critical path is calculated automatically, with float, near-critical work, multiple critical paths and deadline analysis. Resources get a histogram with automatic levelling of overallocation, and multiple baselines let you track deviations from the original plan.

Live demo → All releases → GitHub →

Release notes

v2026.9.0 · 2026-09-02

This is a substantial planning-workflow release: 287 commits since v2026.8.1 concentrate on a single, accessible task grid; explicit day and hour work; more capable reporting; safer extension handling; and reliable saving and resource leveling. The headline features are backed by browser, planning, library and MCP regression coverage rather than being isolated interface changes.

Added

  • One virtual, accessible task grid now powers both the Gantt's task list and the full Table view. It virtualizes large task sets while keeping keyboard cell navigation, selection, editing, pinning and row operations consistent between the two surfaces. The grid has a complete column registry, a column chooser with recently used fields, and personal per-surface column and scroll preferences.
  • Spreadsheet-style task editing is now available in that grid. Multi-cell TSV copy/paste is planned and applied atomically, preserves supported values instead of flattening them to text, repeats a pasted tile where appropriate, and skips read-only cells. Task assignments, scheduling and progress fields can be edited from the same surface.
  • Dependencies can be edited directly in a task-grid cell. The relation editor supports the relation details and linked-task navigation needed by the former dedicated Relationships surface; it also preserves external relation tokens rather than turning them into unstable local links.
  • Projects can define and use personal task types. A type is reusable on the local installation while its stable identity and readable name are stored with the project, so tasks remain intelligible after IFC exchange or on another installation.
  • Task duration has an explicit per-task unit: Days or Hours. Mixed day/hour projects keep the unit that the planner chose; an hour task consumes real working minutes in its effective calendar instead of being silently converted to a day count. The same unit survives IFC, MSPDI and P6 round-trips; CSV remains day-based and does not claim to preserve it.
  • Calendars can now express a configurable intra-day break from their simple shift pattern. The resulting working-time bands are used by hour scheduling, resource loading and leveling; users can therefore model, for example, a lunch break without manually constructing every weekday band.
  • The resource-leveling core gained controlled interruption and shared-capacity foundations. It can insert calendar-valid pauses into work (including hour-mode tasks), level a chosen task scope while treating the rest as fixed load, apply per-task overrun ceilings, and take an external pool ledger into account. A headless resource-library distributor can use that ledger to place document inputs sequentially against their remaining shared capacity; this release does not yet expose that cross-document distributor as a user-facing screen or write-back action.
  • Gantt reports gained clearer planning controls. Reports can use A2 paper, show a baseline overlay, follow the current filtered/grouped view, display a status or progress line, colour bars by task/category/resource/automatic mode, and optionally compress non-working days. The compressed timeline also uses alternate week bands so adjacent weeks remain readable.
  • Saved filter presets are available from the filter workflow, and the resource panel can limit its displayed resources to the current task selection.
  • Document-bound AutoSave is now available next to Save. Once a project has a known writable IFC file, the user may enable periodic writes back to that file. It deliberately remains separate from crash recovery: unsaved documents are never overwritten and recovery snapshots continue to protect changed open documents.
  • The interface can now follow the operating system or browser colour scheme. A new opt-in switch in Settings and the welcome dialog resolves the system preference to Light or Dark, reacts live while the app is open, and keeps the resolved theme through the first paint so the transition does not reintroduce a startup flash. High Contrast remains an explicit manual choice.

Changed

  • The Table view is no longer a separate editor with different interaction rules. It reuses the Gantt task-grid core, and the old Relations tab was retired after relationship editing and navigation reached parity in both grid surfaces.
  • The Gantt is easier to navigate and reposition. Arrow-key navigation now works in the Gantt and histogram, bars can be moved vertically to another task row, the ribbon exposes Fit to project, and hour-bar dragging follows calendar working bands rather than a purely elapsed-time grid.
  • The report preview was redesigned as a bounded, progressive page renderer. It renders pages locally at a selected quality, keeps a compact control strip and scroll position, and avoids creating one unbounded set of data URLs for a large report.
  • Undo/redo, document activation and grid preferences now use a session event model with document-aware boundaries. This keeps a document's history from being offered against another open document while still allowing deliberate personal grid-preference changes to be undone.
  • Extensions and their stored catalog data are now validated before they can become runnable. Invalid manifests, JavaScript, ZIP packages and corrupt IndexedDB records are classified and shown in quarantine instead of being treated as installed extensions; repaired storage replaces the matching quarantine entry atomically.
  • The post-update experience is now driven by a local, versioned highlight catalog. Its fixed primary/secondary-card structure, localized copy and measured release statistics have explicit verification, so an update can show curated product changes without depending on a live release page.

Fixed

  • Hour-mode scheduling and leveling now measure work on the task's real calendar. Fixes cover split tasks, calendar-aware delays and lags, effective hour bands, non-working gaps and the distinction between calendar feasibility and capacity. Started and completed tasks are correctly retained as fixed load instead of being shifted by leveling.
  • The task grid received a focused usability and accessibility repair pass. Tab, Shift+Tab and Escape no longer trap keyboard users; AltGr and macOS Option can still start cell editing; the active cell follows the selected task; dropdowns show their full choices; and selection/drop indicators remain visible above cells.
  • Grid geometry now remains usable at narrow sizes. Column resizing and dragging cover the intended interaction area, the chooser is constrained to the window, the last header is not obscured by its add control, and the Gantt/table splitter reserves sensible column space.
  • Report preview quality switches no longer race stale image work. Pages are rasterized and cached locally with per-page budgets, object URLs are replaced safely, and the preview remains sharp without growing without bound on long reports.
  • The MPP reader stops immediately when its monthly cursor cannot advance, preventing a stationary cursor from continuing through an invalid month traversal.
  • Undo and snapshot handling now crosses Immer's draft boundary explicitly. The shared helper preserves the distinction between a producer's original state and its current draft, with a behavioral regression test for the invariant. Immer is also pinned to the exact reviewed version so local dependency updates cannot silently test different state semantics than CI.
  • Collapsed ribbon groups retain readable labels, and long tooltips wrap instead of escaping the application window.

Documentation

  • Added English and Dutch in-app guides for personal task types, and updated the calendar/hour planning guide to describe explicit units, safe conversion, working-time bands and breaks.
  • Updated the English and Dutch recovery guide to distinguish always-on crash recovery from the opt-in writable-file AutoSave switch, including its browser permission boundary.
  • Expanded the report, resource/histogram, filter and shortcut guides to cover the new controls and navigation. The release also adds regression documentation for the shared grid, Gantt interaction boundaries, extension validation and release-highlight contract.

Bekijk alle releases op GitHub →