The ArcGIS Cheat Sheet Pack

Ten dense quick-reference cards distilled from the ArcGIS Compendium. Find any answer in under ten seconds; chapter references point into the eight volumes.

Map Viewer at a Glance

One-page reference for the ArcGIS Online Map Viewer. Left toolbar = what is in the map (Contents). Right toolbar = what you do to the selected layer or the map (Settings). Full treatment: Compendium Chapter 6 (Map Viewer Complete Reference).

Left toolbar (Contents)

Right toolbar (Settings)

Most panes act on the currently selected layer in the Layers panel — select first, then configure. Entries vary with layer type and your org privileges.

Save and share semantics

• Nothing autosaves. Closing the tab discards unsaved configuration. Save early via Save and open > Save.
• Saving writes configuration into the web map item: layer order, styles, filters, pop-ups, labels, bookmarks, charts, and the current extent (which becomes the map's opening extent).
• Feature edits are different: the Edit tool commits to the layer the moment you finish a feature. No map save required, and no map save will undo them.
• Styling in a map is an override. It never changes the layer item's defaults or other maps using that layer. To push a style back to a layer you own, use the layer's options menu (Save layer).
• Save as creates a new map item and leaves the original untouched. Other users opening your map must Save as — they cannot overwrite your item (the exception: members of a shared update group the item is shared to can save over it).
• Sharing is per item. A public map with private layers is broken for everyone but you. Accept the update-sharing prompt or fix each layer's sharing yourself.

Where commonly-hunted things hide

Five settings that live on the item page, not in the map

Open via Content > (item) > Settings unless noted.

Watch out: Sharing the map without sharing its layers. The map looks perfect to you because you own everything; everyone else opens a blank or partially broken map, and nobody tells you. When the share dialog warns that layers are shared more narrowly than the map, deal with it then — do not dismiss it.

Arcade Quick Reference

Compact reference for ArcGIS Arcade. The full tutorial is Compendium Chapter 8 (Arcade from Zero to Fluent); pop-ups and labels are Chapter 9, styling expressions Chapter 7, dashboards Chapter 28, forms Chapter 30, attribute rules Chapter 14.

Syntax essentials

Most-used functions by task

Where Arcade runs (profiles)

An expression that compiles in one profile can fail in another — test in the profile you will use.

Watch out: Calculate field on a hosted feature layer writes values immediately and permanently. There is no undo. A wrong expression silently overwrites every row it touches. Prove the expression in a pop-up or on a copy of the layer first, and calculate against a filtered selection before running it on everything.

Gotchas checklist

• $feature takes field names, not aliases. Check the item page field list.
• Null in any math or comparison poisons the result. Guard with DefaultValue/IsEmpty.
• Month() is zero-based (January = 0, December = 11); Weekday() starts at 0 = Sunday.
• Filter() conditions are SQL-like strings: single quotes for text, @varName to inject Arcade variables. Never concatenate values into the string.
• Request only needed fields in FeatureSetByName(..., ["FIELD"]) — pop-ups get much faster.
• Broken pop-up expressions render blank, not as errors. Test in the expression editor.
• Avoid for loops over large FeatureSets; use Filter, Sum, GroupBy so the server does the work.

15 copy-paste snippets

1. Null-safe display — use when a field may be empty and you do not want "null" showing.

DefaultValue($feature.OWNER, "Not recorded")

2. Combine fields, skipping blanks — use when building one line from sometimes-empty parts.

var parts = [$feature.STREET, $feature.CITY, $feature.STATE];
var out = [];
for (var i in parts) {
  if (!IsEmpty(parts[i])) { Push(out, parts[i]) }
}
Concatenate(out, ", ")

3. Thousands separators — use when raw numbers are unreadable.

Text($feature.POP2020, "#,###")

4. Readable date — use when showing a date field in a pop-up or label.

Text($feature.INSTALLED, "MMM D, Y")

5. Days since — use when flagging overdue inspections or stale records.

Round(DateDiff(Now(), $feature.LAST_INSP, "days"), 0)

6. Bucket a number — use when classifying a value for styling or display.

When($feature.SCORE >= 80, "Good", $feature.SCORE >= 50, "Fair", "Poor")

7. Translate codes without a domain — use when the layer stores codes but no domain exists.

Decode($feature.STATUS, 1, "Open", 2, "Closed", "Unknown")

8. Show the domain description — use when a coded value domain exists and you want its label.

DomainName($feature, "STATUS")

9. Safe percentage — use when dividing fields that can be zero or null.

IIf($feature.TOTAL > 0, Round($feature.PART / $feature.TOTAL * 100, 1) + "%", "n/a")

10. Acres from geometry — use when there is no area field or it is stale.

Round(AreaGeodetic($feature, "acres"), 2)

11. Value from an intersecting layer — use when a pop-up needs another layer's attribute without a join. Use if/else, not IIf, so the attribute is never read from a null feature.

var zones = FeatureSetByName($map, "Zoning", ["ZONE_CODE"]);
var z = First(Intersects(zones, $feature));
if (IsEmpty(z)) { return "No zone" }
return z.ZONE_CODE

12. Count related records — use when a parent pop-up should show how many children exist.

Count(FeatureSetByRelationshipName($feature, "Inspections"))

13. Sum a field across related records — use when totaling child values in the parent.

var insp = FeatureSetByRelationshipName($feature, "Inspections", ["COST"]);
Sum(insp, "COST")

14. Two-line label — use when a label needs a name plus a stat.

$feature.NAME + TextFormatting.NewLine + Text($feature.CAPACITY, "#,###")

15. Dashboard data expression: grouped counts — use when a dashboard element needs statistics the layer does not expose. See Compendium Chapter 28 (Dashboards).

var fs = FeatureSetByPortalItem(Portal("https://www.arcgis.com"),
         "<item-id>", 0, ["STATUS"], false);
GroupBy(fs, "STATUS",
  {name: "total", expression: "1", statistic: "COUNT"})

Analysis Tool Picker

Find your question, run the tool, apply the sanity check before trusting the output. Credit flags are qualitative — rates change; see Compendium Chapter 2 (The ArcGIS Ecosystem). Legend: None = Pro geoprocessing on local data; Std = standard Online analysis credits, scales with feature count; High = premium service (routing, GeoEnrichment, raster/elevation), scales fast. Tool names show Online first, then Pro where they differ.

Proximity

Depth: Compendium Chapter 16 (Proximity and Overlay).

Overlay and combine

Summarize and join

Patterns and statistics

Depth: Compendium Chapter 17 (Statistical and Pattern Analysis).

Network

Depth: Compendium Chapter 18 (Network Analysis). All of these use street-network routing, not straight lines.

Raster and zonal

Depth: Compendium Chapter 19 (Terrain and Raster Analysis) and Chapter 15 (Imagery and Rasters).

Naming traps

• Overlay Layers (Online) is one tool with a mode dropdown; Pro splits it into Intersect, Union, and Erase.
• Find Closest (Online; called Find Nearest in Map Viewer Classic) offers straight-line or travel mode — the travel option bills like a network tool.
• Join Features (Online) covers both attribute and spatial joins; Pro separates Add Join from Spatial Join.
• Pairwise tool variants in Pro (Buffer, Clip, Erase, Intersect) are faster equivalents for most everyday uses.

Before you run anything

• Suitable projected coordinate system, or geodesic distance option enabled — Compendium Chapter 3 (Coordinate Systems and Projections)
• Filter to only the features you need — faster runs, fewer credits
• Check the "use current map extent" toggle (Online); it silently includes or excludes data
• Field types match the job: numeric stats need numeric fields, joins need matching key types
• In Online, read the estimated-credits dialog before clicking Run
• Name outputs so you can tell run 3 from run 4 next week

Watch out: The costliest mistake here is running a credit-hungry tool (Enrich Layer, Generate Travel Areas, Interpolate Points, raster analysis) against an entire large layer when you meant a filtered subset — with the extent toggle set wrong. Credits are spent even when the result is useless. Filter first, confirm the extent toggle, and read the credit estimate before every run.

Projections Quick Card

One-page lookup for choosing, checking, and fixing coordinate systems. Full treatment: Compendium Chapter 3 (Coordinate Systems and Projections).

Pick a system by task

Decision shortcut: display on the web = Web Mercator, measure or analyze = a local projected system, store and share = WGS84, compare sizes = equal-area.

The four systems you will actually meet

Checklist before any analysis:

• All inputs share one coordinate system (mixed inputs cause misalignment and slivers — Compendium Chapter 16)
• That system is projected, local, and suited to the measure (equal-area for area, conformal for shape)
• Units confirmed (feet vs meters is a classic State Plane bug)
• Datum transformation set when converting between NAD27, NAD83, and WGS84 — ignoring the prompt shifts every feature by a systematic offset (locally uniform, varies by region)

Geodesic vs planar measurement

The rule: if the data is in Web Mercator or WGS84, or covers more than one zone's worth of ground, measure geodesically. Map Viewer's measure tools work geodesically. In Pro, pick the geodesic option in the Measure tool, in right-click field > Calculate Geometry, and in tools like Buffer (choose the geodesic method). Arcade has geodesic geometry functions for pop-ups and calculated fields (Compendium Chapter 8).

Buffers deserve special mention: a planar buffer on Web Mercator data is not a circle on the ground and its size error grows with latitude. Use geodesic buffers (Compendium Chapter 16).

Project vs Define Projection

Two tools in Data Management Tools > Projections and Transformations that sound alike and do opposite things:

Watch out: Running Define Projection to "fix" a layer that draws in the wrong place is the single most damaging projection mistake. It relabels the coordinates without converting them, so the data lands anywhere from a few hundred meters off to a different continent — and the file now lies about what it is, which poisons every later workflow. Define Projection is for correcting a wrong or missing label only. If the data needs to be in a different system, use Project.

Fast diagnostics

Defaults worth setting in Pro

• A new map adopts the coordinate system of the first layer added — and since new maps usually open with a basemap already in them, that means Web Mercator. Set it deliberately: right-click the map in Contents > Properties > Coordinate Systems.
• Set the geoprocessing environment Output Coordinate System when a whole workflow should stay in one system (Compendium Chapter 22).
• When Pro prompts for a geographic transformation, choose one — do not dismiss the warning.
• Check a layer's system anytime via the layer's Properties > Source in Pro; for a hosted layer in ArcGIS Online, the spatial reference is listed on its service (REST) page rather than the item details page (Compendium Chapter 32).

Layer and Format Picker

Use this sheet when you are staring at "Add layer" or "New item" and need to know what a layer type can do, or what a file will turn into after upload. Deep treatment of each layer type is in Compendium Chapter 10 (Hosted Feature Layers), Chapter 15 (Imagery and Rasters), and Chapter 35 (ArcGIS Enterprise).

Layer type matrix

Quick rules of thumb:

• Need pop-ups, filters, or editing → it must be (or be backed by) a feature layer.
• Need speed on data that never changes → tile or vector tile.
• Someone else's server, many sublayers → map image; you consume it, they maintain it.
• If a layer refuses to restyle in Map Viewer, check its type first — tiles and media are pre-rendered by design, not broken.

Import format table

All of these upload from Content > New item, or straight into a map from the Add layer menu in Map Viewer. Full walkthroughs are in Compendium Chapter 11 (Creating Data).

Format decision in one line: have Pro → file geodatabase; have coordinates in a spreadsheet → CSV; handed a shapefile → zip it; handed KML → convert it.

Hosted layer vs file dropped into a map

Small files can be added straight into a single map instead of becoming a hosted layer item. The convenience is real; so is the trap.

Pick hosted when any of these is true:

• More than one map, app, or person will use the data
• Anyone will ever edit it
• The dataset is more than trivially small
• You need views, sharing control, or field-level tweaks (Chapter 10)

Pick in-map only when all of these are true:

• Throwaway or one-time visual check
• Tiny file
• You will never need it in another map

Watch out: Dropping the same file into several maps creates independent embedded copies. A fix or restyle in one map changes nothing anywhere else, and months later nobody can say which copy is current. If the data matters at all, publish it once as a hosted feature layer and add that layer everywhere.

Ten-second answers

Sharing and Permissions Checklist

Sharing in ArcGIS Online is per-item, not per-app. An app can be public while its map or layers are private — the app loads, the content doesn't. Work the chain from the bottom up. For hosted layer mechanics see Compendium Chapter 10 (Hosted Feature Layers); for admin roles and privileges see Compendium Chapter 34 (Administration).

The sharing chain

Every viewer must be able to reach every link. One private link breaks the whole chain.

Rule: the sharing level of every item must be equal to or broader than the app's audience. Public app means public map means public layers.

Chain pre-flight:

• Open the app's item page and its configuration — identify every map it uses (most app items list their web map in the item details)
• Open each web map in Map Viewer — walk the full layer list, including group layers, hidden layers, and any basemap overrides; each shares independently
• Check Share on the app, each map, each layer: all match the intended audience
• Don't work from memory — open the actual map and enumerate; forgotten reference layers are the classic miss
• Test in a private/incognito browser window while signed out (public) or signed in as a target-audience user (group)

Group sharing steps

For sharing with a specific team instead of the whole org or public.

• Create the group: Groups > Create group — set who can view, who can join, who can contribute
• Decide membership type: invite-only for controlled access; request-to-join only if you will actively review requests
• Invite members, or add them directly if your role allows
• Share the app, map, and all layers to the group (all three levels — the chain rule still applies)
• If members will edit each other's items, this needs a shared update group — it must be created with that capability enabled; it cannot be switched on later
• Verify: sign in as a group member (or ask one) and open the app
• Document the group's purpose in its description so the next admin knows why it exists

Master + view pattern for public data

Never share your editable master layer publicly. Publish a read-only view instead. Details in Compendium Chapter 10 (Hosted Feature Layers).

• Keep the master hosted feature layer private or org-only
• From the master's item page: Create View Layer
• In the view's settings, disable editing entirely
• Restrict the view's fields — hide collector names, phone numbers, internal notes, anything you don't need exposed. This is the real protection: hiding a field only in the pop-up is cosmetic — it stays queryable through the service
• Apply a definition filter if only some features are public (e.g., status = approved)
• Share the view (not the master) to Everyone
• Build the public map from the view, the internal editing map from the master
• Re-check the view after any schema change on the master — new fields may appear in the view

Editable-layer exposure check

Run this on every layer shared beyond your team. Anonymous editing on a public layer means anyone on the internet can add, change, or delete your features.

• Item page > Settings > editing section: is editing enabled?
• If enabled and the layer is public: is that genuinely intended (e.g., a crowdsourcing layer)?
• If crowdsourcing: restrict operations to add-only; disable update and delete
• Turn off "editors can see all features" / "editors can edit all features" unless required
• Disable export/download on the item unless you mean to offer raw data — but remember: on a public feature layer, anyone can still read the data through queries; export settings control convenience, not access
• Check delete protection is on for anything you cannot afford to lose
• Confirm attachments don't contain sensitive photos or documents before exposing them
• Check sync: offline-enabled layers can be pulled in full by anyone with access

Watch out: Sharing an editable master layer to Everyone is the single most damaging mistake in this topic. It hands the public full write access to your production data — vandalism, mass deletes, and junk features, often unnoticed for weeks. Always publish a read-only view for public consumption and keep the master private.

Public-launch checklist

Final gate before you send the link out.

• ☐
  1. App, map, and every layer shared to Everyone (walk the full chain)
• ☐
  2. Public layers are read-only views, not editable masters
• ☐
  3. Sensitive fields removed at the view level, not just hidden in pop-ups (Compendium Chapter 9) — pop-up hiding doesn't stop service queries
• ☐
  4. No subscriber or premium content in the map — for anonymous users it either demands a login, or, if you've authorized public access to it, consumes your org's credits on their behalf
• ☐
  5. Custom utility services (geocoder, routing, print) are shared and won't leak credits or credentials
• ☐
  6. Tested the exact public URL in a signed-out incognito window — no login prompt, everything draws
• ☐
  7. Tested on a phone — public users are mostly mobile
• ☐
  8. Pop-ups, labels, and symbology reviewed for internal jargon or draft notes
• ☐
  9. Item pages have real titles, summaries, and thumbnails — they're publicly visible metadata
• ☐
  10. Delete protection enabled on the app, map, and layers; ownership assigned to a durable account, not a departing intern

Fast diagnostics

More failure patterns in Compendium Chapter 39 (Troubleshooting Encyclopedia).

Field Apps Chooser and Offline Checklist

Three mobile apps, three metaphors: Field Maps is map-first, Survey123 is form-first, QuickCapture is button-first. Pick by workflow, not by habit. Full treatment of all three: Compendium Chapter 30 (Field Maps, Survey123, QuickCapture). End-to-end walkthrough: Compendium Chapter 37 (Worked Project - Field Collection).

Decision matrix

Ten-second chooser

• You must see or edit existing features on a map → Field Maps.
• You need branching logic, repeats, or signatures → Survey123.
• You need one-tap speed and no form at all → QuickCapture.
• You need map context and a complex form → Field Maps for the map, launching a Survey123 form from a pop-up link on the feature. Chapter 30 covers the app-link pattern.
• Data lands in hosted feature layers either way: publishing, views, and sync settings are Compendium Chapter 10 (Hosted Feature Layers); field design, domains, and relationships are Chapter 12 (Schema Design).

Offline pre-flight checklist

Run this before any crew leaves the building. Web vs. Pro editing behavior: Compendium Chapter 13 (Editing Workflows).

Layers and map

• Sync enabled on every editable hosted feature layer (item page settings).
• Offline mode enabled on the web map itself (map item settings, offline section).
• Basemap is export-enabled, or you have sideloaded a tile package to the device. A standard basemap that blocks export is the most common "can't take offline" cause.
• Offline map areas pre-defined where crews work in the same zones (Field Maps Designer); otherwise confirm on-device download works.
• Editing settings match the job: add-only vs. full edit, and whether editors see only their own features.

Form and schema

• Domains and default values set so pick lists work without connectivity (Chapter 12).
• Attachments enabled on the layer if photos are required.
• Photo capture size set in the app settings, not left at device maximum.
• Related tables published in the same service as the parent layer if the workflow needs them.

People and devices

• Every field account can sign in and holds the right user type and app license (Compendium Chapter 34, Administration).
• Full dry run on the actual device in airplane mode: open map, collect a feature, attach a photo, reconnect, sync, verify the record in the office map.
• Sync cadence agreed: end of shift minimum, Wi-Fi for attachment-heavy loads.
• Someone in the office owns watching for sync errors during the campaign.

Watch out: Never change a layer's schema, disable sync, or overwrite the service while crews hold offline areas. Doing so invalidates their downloaded copies, and unsynced field edits can become unrecoverable. Freeze the schema for the life of the field campaign; if a change is unavoidable, have every device sync in first, then re-download after the change.

Top five sync gotchas

Sync error messages and their fixes are catalogued in Compendium Chapter 39 (Troubleshooting Encyclopedia).

Quick reference: what each app cannot do

Schema Design Checklist

Use this before you publish a layer or hand a form to field crews. Full treatment: Compendium Chapter 12 (Schema Design). Schema decisions are cheap before data exists and expensive after.

Field-type selection

Watch out: A field's type is permanent once data exists. You cannot convert a populated text field to a date or number field in place — the only fix is add a new field, calculate values across, repair every map, form, pop-up, and app that referenced the old field, then delete it. Storing dates or numbers as text is the single most expensive schema mistake. Decide types before the first row exists.

Naming rules

Coded domain vs free text

Rule of thumb: if you will ever chart or filter by it, use a domain. "Oak / oak / OAK / Oaktree" in free text costs a cleanup project later; adding a code to a domain costs a minute.

Defaults and required flags

Editor tracking and GlobalIDs

• Turn both on before anyone edits. Editor tracking is a layer setting — in ArcGIS Online, on the hosted feature layer's item Settings tab (Compendium Chapter 10). GlobalIDs are present on most hosted layers automatically and are added when sync is enabled; if you publish from Pro, add them before publishing.
• Editor tracking records who created and last edited each feature, and when. For a hosted layer it is usually your only audit trail, and it powers ownership-based editing restrictions.
• GlobalIDs are required for offline sync in Field Maps and key the attachments plumbing. Enabling them mid-project on an offline workforce invites sync trouble — do it on day one.
• Retroactive enabling backfills nothing: edits made before tracking was on have no history.

Attachments: yes or no

Enable attachments when photos or documents belong to a specific feature (pole photo, permit PDF). Skip them when:

• Images are large and numerous — storage counts against your organization (Compendium Chapter 2).
• The file relates to the whole dataset, not one feature — store it as a separate item.
• You need to query by content — attachments are opaque blobs; store descriptive fields alongside.

Enabling attachments later is possible, but decide before designing field forms so crews capture photos from day one.

Related table or more fields

Relationships need a key: GlobalID on the parent, GUID field on the child. Design them together — retrofitting keys onto loose tables is manual work. Details in Compendium Chapter 12.

Cost of change after data exists

12-point pre-collection checklist

1. [ ] Every field's type checked against the table above — no dates or numbers stored as text
2. [ ] Field names lowercase, no spaces, no reserved words; final (not placeholders)
3. [ ] Every field has a plain-language alias
4. [ ] Every categorical field has a coded value domain, including an "Unknown" or "Other" code
5. [ ] Defaults set on high-volume fields; no misleading defaults
6. [ ] Required flags limited to genuinely mandatory fields
7. [ ] GlobalIDs enabled
8. [ ] Editor tracking enabled
9. [ ] Attachments decision made and configured
10. [ ] Repeating data moved to related tables with keys defined
11. [ ] Test features created, edited in the real form (Compendium Chapter 13), then deleted
12. [ ] Schema reviewed by one person who did not design it

If all twelve pass, publish. If any fail, fix them now — every row collected multiplies the cost of the fix.

Styling Decision Guide

Match your data's shape to a style family first, then pick classification and color. Full click paths and every style option: Compendium Chapter 7 (Styling and Smart Mapping). Color theory and visual hierarchy: Compendium Chapter 4 (Cartographic Design).

Step 1: What shape is your data?

If a field can be styled with a computed value instead of raw data (a ratio, a category from thresholds), write an Arcade expression rather than adding a field — Compendium Chapter 8 (Arcade from Zero to Fluent).

Step 2: Classification method — each one has a bias

Checklist before committing:

• Looked at the histogram in the style pane (outliers? skew?)
• Kept classes to roughly three to seven
• Rounded break values in the legend to numbers a human can repeat
• If maps will be compared side by side, used identical manual breaks on all of them

Step 3: Color ramp rules

Colorblind rule: never let red vs. green carry the only meaning. Prefer ramps flagged colorblind-friendly in the ramp picker, and vary lightness as well as hue so the ramp survives grayscale. When in doubt, run the map through a color-vision simulator before publishing.

Watch out: The single most damaging styling mistake is a choropleth of raw counts — coloring polygons by totals when the polygons differ in size or population. Big empty counties look "high" simply because they're big. Normalize (per capita, per square mile, percent) or switch to size-based symbols. No classification method or ramp can rescue an unnormalized count map.

Step 4: Dense points — clustering vs. binning vs. heat map vs. dot density

A heat map is a visual impression, not analysis. For statistically defensible hot spots, use the pattern-analysis tools in Compendium Chapter 17 (Statistical and Pattern Analysis).

Ten-second pre-publish check

• Counts → size; rates → color
• Choropleth normalized
• Break values defensible and rounded
• Ramp direction matches intuition on this basemap
• Survives a colorblind simulator and grayscale
• Checked at the actual zoom levels the audience will use
• Legend reads in under ten seconds without you explaining it

Working in Pro instead of Map Viewer? Same decisions apply; the mechanics live in Compendium Chapter 23 (Symbology and Labeling).

Troubleshooting Triage Card

Run the three checks in order. Most failures die at check 1 or 2. If all three pass, go to the referenced chapter for the full diagnosis tree.

Before anything else: the 60-second sweep

• Hard-refresh the browser (or try an incognito window) — cached apps lie.
• Confirm which account you are signed into, and which organization.
• Open the item page of the thing that is broken. Errors often show there first.
• Ask: did anything change since it last worked? (Sharing, schema, rename, delete.)

The triage table

Watch out: Never "fix" a broken hosted feature layer by deleting it and republishing. The new item gets a new ID, which silently breaks every map, app, dashboard, form, and field deployment pointing at the old one — and can destroy field-collected data that only lived in that layer. Fix layers in place (overwrite, update definition, edit settings). See Compendium Chapter 10 (Hosted Feature Layers).

If all three checks pass: escalate with evidence

Collect these before filing a ticket or asking a colleague. It halves the round trips.

• Item ID of the broken layer, map, or app.
• Exact error text, plus a screenshot.
• Does it fail in an incognito window? For a different user?
• Does the layer's REST endpoint respond? (Open the service URL from the item page — Compendium Chapter 32, REST Services.)
• When did it last work, and what changed since?

Full symptom-by-symptom trees live in Compendium Chapter 39 (Troubleshooting Encyclopedia).