Moving a Small Team from Trello to Asana: Plan and Verify History Preservation

By Clayton

Plan the move around two deliverables: active work your team can use in Asana and historical context it can still retrieve. Prepare and verify both before switching. Asana documents a Trello migration route through CSV export and import, but that route does not establish a complete transfer of project history. Asana’s migration guidance

“Without losing project history” needs a practical definition. Trello CSV excludes comments, and an individual board’s JSON export contains only the latest 1,000 actions, including comments. Neither establishes that every past decision will survive the move. Trello export documentation

Proceed if your team can validate its active work in Asana and retrieve required history through an accepted archive or retained Trello access. Pause if original comments, authors, timestamps, or complete activity chronology must appear natively in Asana: the reviewed documentation does not establish that outcome.

This guide draws on official documentation recorded as accessed October 21, 2026. No migration was performed. The rehearsal and cutover procedures below are editorial recommendations, not tested results or a vendor-certified method.

1. Decide what your team must keep

Before exporting, write down what would make the move acceptable. “All our cards arrived” is too narrow if the team also needs the discussion explaining why a deadline changed.

Use this worksheet for each board:

• Active work: Which cards, owners, deadlines, lists, and dependencies must become usable in Asana?
• Historical context: Which completed or archived cards, comments, approvals, and decisions must remain retrievable?
• Files: Which attachments need independent copies, and which may remain links?
• Historical fidelity: Is readable source history sufficient, or must original authorship and timestamps exist inside Asana?
• Access: Who must be able to open the destination, retained files, and source records?
• Acceptance: Who checks each requirement and decides whether an exception is acceptable?

Inventory automations, Power-Ups, integrations, and cross-card links separately. Their migration was not established by this research. Assign each a verification task before relying on it after cutover.

Also budget for export-plan eligibility, overlapping subscriptions, file storage, preparation, validation, training, and workflow reconstruction. These are planning categories, not estimates of cost or duration. A small board with essential historical decisions may require more checking than a larger board of straightforward tasks.

2. Export task data and retain historical context

Trello allows board members to export JSON. Board CSV export requires a Premium Workspace, while Premium Workspace exports require a Workspace admin. Confirm eligibility and permissions before scheduling the move. Use Atlassian’s export instructions for current requirements; Asana’s Trello migration page retains older plan terminology and menu wording. Trello export documentation · Asana’s migration guidance

Keep an untouched export separate from the CSV you prepare for import. Record the board, export time, person responsible, and intended scope so reviewers know what the snapshot represents.

Comments and older decisions

CSV does not contain Trello comments. Individual board JSON includes only the latest 1,000 actions, including comments; the limit applies to actions, not just comments. Atlassian directs users to Workspace export for all comments. That guidance does not guarantee preservation of every kind of activity history or its recreation inside Asana. Trello export documentation

Check several older decisions your team needs. Confirm that someone can locate and read them in the retained material. Before accepting a downloaded file as an archive, check both its required contents and its usability.

Archived cards

Standard Trello CSV export omits archived cards. Atlassian documents appending .csv to the board URL to export open and archived cards. If archived work is in scope, use that documented method and compare the result with your inventory. Trello export documentation

Attachments and source links

For Premium Workspace exports, selecting Include raw attachments packages files in their original formats. Otherwise, exports contain links to Trello-hosted attachments. Coverage of externally hosted files and automatic creation of Asana attachments remain unverified. Trello export documentation

Open required retained files and check external links separately. Keep source card or comment URLs alongside the relevant work, but remember that links depend on the source remaining available. Private Trello links still require appropriate board access. Trello link-sharing guidance

3. Map Trello work to Asana before importing

Prepare a working CSV using Asana’s documented headers and field order. Use workspace or organization user email addresses, choose one assignee per task, and format due dates as month/day/year. Collaborators are a separate field, so decide who owns a card when Trello lists several members. Asana CSV preparation guidance

Use the table below to plan your mappings. Each proposed destination needs validation during rehearsal; automatic conversion is not established.

Trello data	Intended destination	Preparation and verification
Card title and description	Task name and description	Compare the imported wording with the source, including important links.
Lists	Asana sections	Choose the intended organization; check section placement and ordering during rehearsal.
Multiple card members	One assignee plus collaborators	Select an accountable owner and verify assignment using email addresses.
Due dates	Task due dates	Use the documented date format; separately check due times and time zones.
Checklists	Prepared subtasks where appropriate	Create explicit parent-child rows and verify item counts and completion details.
Labels and custom fields	Chosen destination fields	Decide field types and options; compare imported values with the source.
Card and comment URLs	Source references alongside tasks	Confirm that intended users can open them.
Attachments	Retained files or verified destination attachments	Open the files to check access; a URL alone does not establish that a file was uploaded.
Archived or completed cards	Chosen destination state or archive	Verify inclusion and status rather than assuming equivalent treatment.

The worksheet draws on the documented CSV preparation and mapping capabilities, with source-link access checked separately. Asana CSV preparation guidance · Asana advanced CSV options · Trello link-sharing guidance

Two mappings deserve particular attention: subtasks and custom fields. For subtasks, Asana supports a Parent Task column containing exact parent task names, with parent rows placed before child rows. Repeated names resolve to the closest matching row above. This supports deliberately prepared relationships; it does not establish automatic Trello checklist conversion. Asana advanced CSV options

For example, a hypothetical board with two cards named “Launch checklist” could produce an unintended parent-child match. Give the prepared parent rows distinguishable names, update their child references, and verify the resulting relationships.

Trello includes custom-field data in JSON and CSV exports. Asana’s documentation requires a paid subscription for custom fields; imported fields default to project-local scope, and existing field options must match exactly. Export inclusion alone does not prove equivalent field types or successful mapping. Trello custom-field guidance · Asana advanced CSV options

4. Rehearse in a separate Asana project

Choose representative cards from one pilot board. Include a card with multiple members, an older decision thread, a file attachment, an external file link, a checklist, custom fields, and archived or completed work. Include repeated task names if your boards use them.

Before completing the import, review Make changes and inspect how columns were recognized. Malformed values can prevent intended field recognition. Check owners, dates, sections, and field types even if the preview looks plausible. Asana CSV preparation guidance

After importing, use a comparison sheet with four columns: source item, expected result, observed result, and action needed. Check:

• Task counts against the selected source scope, with prepared subtasks counted separately.
• Assignees, collaborators, dates, and section placement.
• Parent-child relationships, checklist coverage, and custom-field values.
• Archived and completed states, checklist completion, due times, time zones, and ordering.
• Required file access and the ability to retrieve historical decisions.
• Source and destination access for the people who will need it.

Counts alone are insufficient. Ask a teammate to answer a concrete question, such as “Why was this deadline moved?” using the proposed archive and links. If the answer requires access that person will lose after cutover, the preservation plan has failed that requirement.

Asana CSV imports add tasks; they do not update existing tasks. Reimporting a corrected file into the same project can therefore create duplicates. Use a fresh rehearsal project for another full trial, or explicitly account for earlier imported tasks before retrying. Asana CSV preparation guidance

Record unresolved differences and assign owners. Treat the pilot as successful only when required checks pass or the team explicitly accepts the remaining exceptions.

5. Set a cutover time and a fallback plan

Once rehearsal passes, write a short cutover plan naming the migration owner, editing cutoff, destination project, acceptance reviewer, and fallback owner. Tell the team where to record work during the transition.

Use this sequence as an operational checklist:

1. Stop Trello changes at the agreed time. Address human editors, administrators, integrations, and automated changes.
2. Take the final exports. Record their timestamps and confirm that required history and files are retained.
3. Prepare the final CSV. Apply the mappings that passed rehearsal, checking any changes since the pilot.
4. Import once into the intended destination. Confirm that rehearsal tasks will not be duplicated there.
5. Reconcile the result. Compare required work, ownership, dates, relationships, files, and history access.
6. Announce acceptance or fallback. State which system is authoritative for new work and who handles exceptions.

Premium observer permissions can help limit changes: observers can view boards and download attachments without editing cards. However, they may still comment or vote when settings allow, and assigning observers does not restrict remaining editors or administrators. Treat observer status as one part of the editing stop. Trello observer permissions

Keep a log of changes made after the final snapshot. Assign someone to reconcile each change manually or through another explicitly verified process. CSV import does not provide incremental synchronization because it adds tasks rather than updating existing ones. Asana CSV preparation guidance

If acceptance fails, the fallback owner should decide whether to resume work in retained Trello boards and reconcile any work already entered in Asana. Trello cannot directly recreate a board by importing its JSON or CSV export, so the export itself is not a one-click rollback. Trello export documentation

6. Make the proceed-or-pause decision

Proceed when the pilot demonstrates that your chosen approach meets the team’s requirements. Use this final acceptance checklist:

• Required active and archived work is accounted for.
• Owners, dates, relationships, and field values have been checked.
• Required files open for their intended users.
• Important historical decisions can be retrieved in the accepted format.
• Responsibility for source access and the archive is assigned.
• Exceptions are resolved or explicitly accepted.
• Cutover and fallback owners know how to reconcile later changes.

Pause if essential comments or files remain inaccessible, source permissions cannot be maintained, or native historical fidelity is mandatory but unverified. A successful task import does not resolve those gaps.

For a team that accepts retained history outside Asana, a verified task import plus a usable archive may meet its needs. For a team that requires the complete original chronology inside Asana, this documented CSV route remains unproven.

Choose one pilot board and write down its acceptance criteria before scheduling the team’s cutover.