What does TTL mean in software engineering?

TTL stands for Time To Live. It specifies how long data, network packets, or cached information remains valid before it expires or is discarded by the system. TTL is used in DNS, caching, networking, and databases.

How do you use TTL in a sentence at work?

You typically say you set a TTL, configure a TTL, or adjust a TTL. Example: We set the TTL on the session cookie to 24 hours. You can also say the TTL expires or the TTL is too high. Do not use TTL as a verb.

Is TTL formal or informal?

TTL is neutral and technical. It is used in formal documentation, code reviews, and casual team conversations. It is the standard abbreviation in the industry, so using it is always appropriate in tech contexts.

What is the difference between TTL in DNS and TTL in caching?

In DNS, TTL tells resolvers how long to cache a DNS record. In caching systems like Redis, TTL tells the system when to delete a cached value. Both work on the same principle but apply to different systems and data.

Why is TTL important?

TTL helps balance freshness and performance. Short TTLs keep data fresh but increase server load. Long TTLs improve performance but risk stale data. Proper TTL configuration is critical for system reliability and user experience.

TTL meaning in tech — Speak Tech English

Commonness	4/5
Versatility	4/5
Formality	CasualFormalNeutral
Spoken ↔ Written	SpokenWrittenBoth
Directness ↔ Diplomatic	DirectDiplomaticDirect
Region	US and UK

Say it like this

✓Set the TTL to 3600 seconds

✓The TTL expired before we could refresh the data

✓We need to lower the TTL to reduce cache staleness

Real examples

in a standup

"We increased the DNS TTL to reduce query load on our nameservers."

in a code review

"Make sure to set an appropriate TTL on session tokens so expired sessions are automatically cleaned up."

in a team meeting

"The database partition failed because records with TTL were not being deleted properly."

Don't say this

Handle with care. TTL has different meanings in different contexts (networking vs. caching vs. database); always clarify which one you mean. Do not use as a verb (say set TTL, not TTL something).

✕We TTL the cache every hour.

✓We set a TTL of one hour on the cache.— TTL is a noun (a value or setting), not a verb. You set or configure a TTL, you do not TTL something.

✕The TTL in DNS and the TTL in Redis work the same way.

✓TTL serves similar purposes in DNS and Redis, but the implementation and impact differ by system.— While both use TTL conceptually, the specific behavior and context matter. Always clarify which system you are discussing.

✕We forgot to TTL the data before deployment.

✓We forgot to set a TTL on the data before deployment.— Use set, configure, or define with TTL as the object, not TTL as the action itself.

Other forms

noun

TTL

"The TTL on this API response is 10 minutes."

noun

TTL value

"We need to increase the TTL value to reduce database load."

phrase

set TTL

"Always set TTL when creating cache entries."

Often used with

set TTLTo assign or configure a time-to-live value

TTL expiresWhen the time-to-live period ends and data becomes invalid

increase/decrease TTLTo extend or shorten the validity period

TTL valueThe specific time duration assigned as TTL

DNS TTLTTL specifically in domain name system contexts

Similar words

expiration timeLess technical; used more in general contexts rather than system design

cache lifetimeMore specific to caching; TTL is broader and applies to packets, records, and sessions too

validity periodGeneric term; TTL is the standard technical abbreviation used in engineering

Opposites

permanent storageno expiration

Featured course

English for Developers Bundle

Full tech-English bundle for meetings, code reviews, and everyday developer communication.

500+ reviews

View

Practice

Try it

4 quick exercises

Pick the most natural phrasing

1. You want to tell your team that cached data should remain valid for 5 minutes. What do you say?

Set the TTL to 5 minutes.The TTL should be 5 minutes.TTL this to 5 minutes.We need to TTL it 5 minutes long.

Complete the sentence

2. If the _______ on the DNS record is too high, clients may cache stale IP addresses.

Spot the mistake

3. Which sentence uses TTL incorrectly?

We set a TTL of 3600 seconds for the authentication token.The Redis cache needs a lower TTL to keep data fresh.Please TTL the old user records from the database.The packet TTL decremented at each network hop.

Rewrite naturally

4. Rewrite this in natural tech English: 'The data should stay valid for thirty seconds before we throw it away.'

Questions

Quick poll

Have you said "ttl" in a standup this week?

Want more structured practice like this? Our English for Programmers course covers real workplace English in depth.

Your badges

XLinkedIn

← Back to home